diff --git a/CONTRIBUTING.md b/CONTRIBUTING.md
index 15aab603c..4b1164232 100644
--- a/CONTRIBUTING.md
+++ b/CONTRIBUTING.md
@@ -13,15 +13,14 @@ Here's what you can do to help:
### Snippet submission and Pull request guidelines
- **DO NOT MODIFY THE README.md FILE!** Make changes to individual snippet files. You can optionally run `npm run build-list` to update the README.md file automatically, based on the changes you have made.
-- **Snippet filenames** must correspond to the title of the snippet. For example, if your snippet is titled `### Awesome snippet` the filename should be `awesome-snippet.md`.
- - Use `kebab-case`, not `snake_case`.
+- **Snippet filenames** must correspond to the title of the snippet. For example, if your snippet is titled `### awesomeSnippet` the filename should be `awesomeSnippet.md`.
+ - Use `camelCase`, not `kebab-case` or `snake_case`.
- Avoid capitalization of words, except if the whole word is capitalized (e.g. `URL` should be capitalized in the filename and the snippet title).
- - If there are parentheses in the title, add them to the filename (e.g. `awesome-snippet-(extra-awesome).md` if your snippet's title is `Awesome snippet (extra awesome)`).
-- **Snippet titles** should have only the first letter of the first word capitalized. Certain words can be in capitals (e.g. `URL`, `RGB`), but this is on a per-snippet basis.
+- **Snippet titles** should have be the same as the name of the function that is present in the snippet.
- All snippet titles must be prefixed with `###` and be at the very first line of your snippet.
- Snippet titles must be unique (although if you cannot find a better title, just add some placeholder at the end of the filename and title and we will figure it out).
- Follow snippet titles with an empty line.
-- **Snippet descriptions** must be short and to the point. Try to explain *how* the snippet works and what Javascript features are used. Remember to include what functions you are using and why.
+- **Snippet descriptions** must be short and to the point. Try to explain *what* the snippet does and *how* the snippet works and what Javascript features are used. Remember to include what functions you are using and why.
- Follow snippet descriptions with an empty line.
- **Snippet code** must be enclosed inside ` ```js ` and ` ``` `.
- Remember to start your snippet's code on a new line below the opening backticks.
diff --git a/README.md b/README.md
index c9dd3b8b4..4cd0838cd 100644
--- a/README.md
+++ b/README.md
@@ -10,131 +10,216 @@
## Table of Contents
### Array
-* [Array difference](#array-difference)
-* [Array intersection](#array-intersection)
-* [Array pull (mutates array)](#array-pull-mutates-array)
-* [Array remove](#array-remove)
-* [Array sample](#array-sample)
-* [Array symmetric difference](#array-symmetric-difference)
-* [Array union](#array-union)
-* [Array without](#array-without)
-* [Array zip](#array-zip)
-* [Average of array of numbers](#average-of-array-of-numbers)
-* [Chunk array](#chunk-array)
-* [Compact](#compact)
-* [Count occurrences of a value in array](#count-occurrences-of-a-value-in-array)
-* [Deep flatten array](#deep-flatten-array)
-* [Drop elements in array](#drop-elements-in-array)
-* [Filter out non unique values in an array](#filter-out-non-unique-values-in-an-array)
-* [Flatten array up to depth](#flatten-array-up-to-depth)
-* [Flatten array](#flatten-array)
-* [Get max value from array](#get-max-value-from-array)
-* [Get min value from array](#get-min-value-from-array)
-* [Group by](#group-by)
-* [Head of list](#head-of-list)
-* [Initial of list](#initial-of-list)
-* [Initialize array with range](#initialize-array-with-range)
-* [Initialize array with values](#initialize-array-with-values)
-* [Last of list](#last-of-list)
-* [Median of array of numbers](#median-of-array-of-numbers)
-* [Nth element of array](#nth-element-of-array)
-* [Pick](#pick)
-* [Shuffle array](#shuffle-array)
-* [Similarity between arrays](#similarity-between-arrays)
-* [Sum of array of numbers](#sum-of-array-of-numbers)
-* [Tail of list](#tail-of-list)
-* [Take every nth element](#take-every-nth-element)
-* [Take right](#take-right)
-* [Take](#take)
-* [Unique values of array](#unique-values-of-array)
+* [`arrayMax`](#arraymax)
+* [`arrayMin`](#arraymin)
+* [`chunk`](#chunk)
+* [`compact`](#compact)
+* [`countOccurrences`](#countoccurrences)
+* [`deepFlatten`](#deepflatten)
+* [`difference`](#difference)
+* [`distinctValuesOfArray`](#distinctvaluesofarray)
+* [`dropElements`](#dropelements)
+* [`everyNth`](#everynth)
+* [`filterNonUnique`](#filternonunique)
+* [`flatten`](#flatten)
+* [`flattenDepth`](#flattendepth)
+* [`groupBy`](#groupby)
+* [`head`](#head)
+* [`initial`](#initial)
+* [`initializeArrayWithRange`](#initializearraywithrange)
+* [`initializeArrayWithValues`](#initializearraywithvalues)
+* [`intersection`](#intersection)
+* [`last`](#last)
+* [`nthElement`](#nthelement)
+* [`pick`](#pick)
+* [`pull`](#pull)
+* [`remove`](#remove)
+* [`sample`](#sample)
+* [`shuffle`](#shuffle)
+* [`similarity`](#similarity)
+* [`symmetricDifference`](#symmetricdifference)
+* [`tail`](#tail)
+* [`take`](#take)
+* [`takeRight`](#takeright)
+* [`union`](#union)
+* [`without`](#without)
+* [`zip`](#zip)
### Browser
-* [Bottom visible](#bottom-visible)
-* [Current URL](#current-url)
-* [Element is visible in viewport](#element-is-visible-in-viewport)
-* [Get scroll position](#get-scroll-position)
-* [Redirect to URL](#redirect-to-url)
-* [Scroll to top](#scroll-to-top)
+* [`bottomVisible`](#bottomvisible)
+* [`current-URL`](#current-url)
+* [`elementIsVisibleInViewport`](#elementisvisibleinviewport)
+* [`getScrollPosition`](#getscrollposition)
+* [`getURLParameters`](#geturlparameters)
+* [`redirect`](#redirect)
+* [`scrollToTop`](#scrolltotop)
### Date
-* [Convert to english date](#convert-to-english-date)
-* [Get days difference between dates](#get-days-difference-between-dates)
-* [JSON to date](#json-to-date)
+* [`getDaysDiffBetweenDates`](#getdaysdiffbetweendates)
+* [`JSONToDate`](#jsontodate)
+* [`toEnglishDate`](#toenglishdate)
### Function
-* [Chain asynchronous functions](#chain-asynchronous-functions)
-* [Compose functions](#compose-functions)
-* [Curry](#curry)
-* [Log function name](#log-function-name)
-* [Pipe functions](#pipe-functions)
-* [Promisify](#promisify)
-* [Run promises in series](#run-promises-in-series)
-* [Sleep](#sleep)
+* [`chainAsync`](#chainasync)
+* [`compose`](#compose)
+* [`curry`](#curry)
+* [`functionName`](#functionname)
+* [`pipe`](#pipe)
+* [`promisify`](#promisify)
+* [`runPromisesInSeries`](#runpromisesinseries)
+* [`sleep`](#sleep)
### Math
-* [Collatz algorithm](#collatz-algorithm)
-* [Distance between two points](#distance-between-two-points)
-* [Divisible by number](#divisible-by-number)
-* [Even or odd number](#even-or-odd-number)
-* [Factorial](#factorial)
-* [Fibonacci array generator](#fibonacci-array-generator)
-* [Greatest common divisor (GCD)](#greatest-common-divisor-gcd)
-* [Hamming distance](#hamming-distance)
-* [Least common multiple (LCM)](#least-common-multiple-lcm)
-* [Percentile](#percentile)
-* [Powerset](#powerset)
-* [Random integer in range](#random-integer-in-range)
-* [Random number in range](#random-number-in-range)
-* [Round number to n digits](#round-number-to-n-digits)
-* [Standard deviation](#standard-deviation)
+* [`arrayAverage`](#arrayaverage)
+* [`arraySum`](#arraysum)
+* [`collatz`](#collatz)
+* [`digitize`](#digitize)
+* [`distance`](#distance)
+* [`factorial`](#factorial)
+* [`fibonacci`](#fibonacci)
+* [`gcd`](#gcd)
+* [`hammingDistance`](#hammingdistance)
+* [`isDivisible`](#isdivisible)
+* [`isEven`](#iseven)
+* [`lcm`](#lcm)
+* [`median`](#median)
+* [`palindrome`](#palindrome)
+* [`percentile`](#percentile)
+* [`powerset`](#powerset)
+* [`randomIntegerInRange`](#randomintegerinrange)
+* [`randomNumberInRange`](#randomnumberinrange)
+* [`round`](#round)
+* [`standardDeviation`](#standarddeviation)
### Media
-* [Speech synthesis (experimental)](#speech-synthesis-experimental)
+* [`speechSynthesis`](#speechsynthesis)
### Node
-* [Read file as array of lines](#read-file-as-array-of-lines)
-* [Write JSON to file](#write-json-to-file)
+* [`JSONToFile`](#jsontofile)
+* [`readFileLines`](#readfilelines)
### Object
-* [Clean JSON object](#clean-json-object)
-* [Object from key value pairs](#object-from-key-value-pairs)
-* [Object to key value pairs](#object-to-key-value-pairs)
-* [Shallow clone object](#shallow-clone-object)
+* [`cleanObj`](#cleanobj)
+* [`objectFromPairs`](#objectfrompairs)
+* [`objectToPairs`](#objecttopairs)
+* [`shallowClone`](#shallowclone)
### String
-* [Anagrams of string (with duplicates)](#anagrams-of-string-with-duplicates)
-* [Capitalize first letter of every word](#capitalize-first-letter-of-every-word)
-* [Capitalize first letter](#capitalize-first-letter)
-* [Check for palindrome](#check-for-palindrome)
-* [Convert string from camelcase](#convert-string-from-camelcase)
-* [Convert string to camelcase](#convert-string-to-camelcase)
-* [Reverse a string](#reverse-a-string)
-* [Sort characters in string (alphabetical)](#sort-characters-in-string-alphabetical)
-* [Truncate a string](#truncate-a-string)
+* [`anagrams`](#anagrams)
+* [`capitalize`](#capitalize)
+* [`capitalizeEveryWord`](#capitalizeeveryword)
+* [`escapeRegExp`](#escaperegexp)
+* [`fromCamelCase`](#fromcamelcase)
+* [`reverseString`](#reversestring)
+* [`sortCharactersInString`](#sortcharactersinstring)
+* [`toCamelCase`](#tocamelcase)
+* [`truncateString`](#truncatestring)
### Utility
-* [3 digit hexcode to 6 digit hexcode](#3-digit-hexcode-to-6-digit-hexcode)
-* [Escape regular expression](#escape-regular-expression)
-* [Get native type of value](#get-native-type-of-value)
-* [Hexcode to RGB](#hexcode-to-rgb)
-* [Is array](#is-array)
-* [Is boolean](#is-boolean)
-* [Is function](#is-function)
-* [Is number](#is-number)
-* [Is string](#is-string)
-* [Is symbol](#is-symbol)
-* [Measure time taken by function](#measure-time-taken-by-function)
-* [Number to array of digits](#number-to-array-of-digits)
-* [Ordinal suffix of number](#ordinal-suffix-of-number)
-* [RGB to hexadecimal](#rgb-to-hexadecimal)
-* [URL parameters](#url-parameters)
-* [UUID generator](#uuid-generator)
-* [Validate email](#validate-email)
-* [Validate number](#validate-number)
+* [`extendHex`](#extendhex)
+* [`getType`](#gettype)
+* [`hexToRGB`](#hextorgb)
+* [`isArray`](#isarray)
+* [`isBoolean`](#isboolean)
+* [`isFunction`](#isfunction)
+* [`isNumber`](#isnumber)
+* [`isString`](#isstring)
+* [`isSymbol`](#issymbol)
+* [`RGBToHex`](#rgbtohex)
+* [`timeTaken`](#timetaken)
+* [`toOrdinalSuffix`](#toordinalsuffix)
+* [`UUIDGenerator`](#uuidgenerator)
+* [`validateEmail`](#validateemail)
+* [`validateNumber`](#validatenumber)
## Array
-### Array difference
+### arrayMax
+
+Returns the maximum value in an array.
+
+Use `Math.max()` combined with the spread operator (`...`) to get the maximum value in the array.
+
+```js
+const arrayMax = arr => Math.max(...arr);
+// arrayMax([10, 1, 5]) -> 10
+```
+
+[⬆ back to top](#table-of-contents)
+
+### arrayMin
+
+Returns the minimum value in an array.
+
+Use `Math.min()` combined with the spread operator (`...`) to get the minimum value in the array.
+
+```js
+const arrayMin = arr => Math.min(...arr);
+// arrayMin([10, 1, 5]) -> 1
+```
+
+[⬆ back to top](#table-of-contents)
+
+### chunk
+
+Chunks an array into smaller arrays of a specified size.
+
+Use `Array.from()` to create a new array, that fits the number of chunks that will be produced.
+Use `Array.slice()` to map each element of the new array to a chunk the length of `size`.
+If the original array can't be split evenly, the final chunk will contain the remaining elements.
+
+```js
+const chunk = (arr, size) =>
+ Array.from({length: Math.ceil(arr.length / size)}, (v, i) => arr.slice(i * size, i * size + size));
+// chunk([1,2,3,4,5], 2) -> [[1,2],[3,4],[5]]
+```
+
+[⬆ back to top](#table-of-contents)
+
+### compact
+
+Removes falsey values from an array.
+
+Use `Array.filter()` to filter out falsey values (`false`, `null`, `0`, `""`, `undefined`, and `NaN`).
+
+```js
+const compact = (arr) => arr.filter(Boolean);
+// compact([0, 1, false, 2, '', 3, 'a', 'e'*23, NaN, 's', 34]) -> [ 1, 2, 3, 'a', 's', 34 ]
+```
+
+[⬆ back to top](#table-of-contents)
+
+### countOccurrences
+
+Counts the occurences of a value in an array.
+
+Use `Array.reduce()` to increment a counter each time you encounter the specific value inside the array.
+
+```js
+const countOccurrences = (arr, value) => arr.reduce((a, v) => v === value ? a + 1 : a + 0, 0);
+// countOccurrences([1,1,2,1,2,3], 1) -> 3
+```
+
+[⬆ back to top](#table-of-contents)
+
+### deepFlatten
+
+Deep flattens an array.
+
+Use recursion.
+Use `Array.concat()` with an empty array (`[]`) and the spread operator (`...`) to flatten an array.
+Recursively flatten each element that is an array.
+
+```js
+const deepFlatten = arr => [].concat(...arr.map(v => Array.isArray(v) ? deepFlatten(v) : v));
+// deepFlatten([1,[2],[[3],4],5]) -> [1,2,3,4,5]
+```
+
+[⬆ back to top](#table-of-contents)
+
+### difference
+
+Returns the difference between two arrays.
Create a `Set` from `b`, then use `Array.filter()` on `a` to only keep values not contained in `b`.
@@ -145,7 +230,168 @@ const difference = (a, b) => { const s = new Set(b); return a.filter(x => !s.has
[⬆ back to top](#table-of-contents)
-### Array intersection
+### distinctValuesOfArray
+
+Returns all the distinct values of an array.
+
+Use ES6 `Set` and the `...rest` operator to discard all duplicated values.
+
+```js
+const distinctValuesOfArray = arr => [...new Set(arr)];
+// unique([1,2,2,3,4,4,5]) -> [1,2,3,4,5]
+```
+
+[⬆ back to top](#table-of-contents)
+
+### dropElements
+
+Removes elements in an array until the passed function returns `true`. Returns the remaining elements in the array.
+
+Loop through the array, using `Array.shift()` to drop the first element of the array until the returned value from the function is `true`.
+Returns the remaining elements.
+
+```js
+const dropElements = (arr, func) => {
+ while (arr.length > 0 && !func(arr[0])) arr.shift();
+ return arr;
+};
+// dropElements([1, 2, 3, 4], n => n >= 3) -> [3,4]
+```
+
+[⬆ back to top](#table-of-contents)
+
+### everyNth
+
+Returns every nth element in an array.
+
+Use `Array.filter()` to create a new array that contains every nth element of a given array.
+
+```js
+const everyNth = (arr, nth) => arr.filter((e, i) => i % nth === 0);
+// everynth([1,2,3,4,5,6], 2) -> [ 1, 3, 5 ]
+```
+
+[⬆ back to top](#table-of-contents)
+
+### filterNonUnique
+
+Filters out the non-unique values in an array.
+
+Use `Array.filter()` for an array containing only the unique values.
+
+```js
+const filterNonUnique = arr => arr.filter(i => arr.indexOf(i) === arr.lastIndexOf(i));
+// filterNonUnique([1,2,2,3,4,4,5]) -> [1,3,5]
+```
+
+[⬆ back to top](#table-of-contents)
+
+### flatten
+
+Flattens an array.
+
+Use `Array.reduce()` to get all elements inside the array and `concat()` to flatten them.
+
+```js
+const flatten = arr => arr.reduce((a, v) => a.concat(v), []);
+// flatten([1,[2],3,4]) -> [1,2,3,4]
+```
+
+[⬆ back to top](#table-of-contents)
+
+### flattenDepth
+
+Flattens an array up to the specified depth.
+
+Use recursion, decrementing `depth` by 1 for each level of depth.
+Use `Array.reduce()` and `Array.concat()` to merge elements or arrays.
+Base case, for `depth` equal to `1` stops recursion.
+Omit the second element, `depth` to flatten only to a depth of `1` (single flatten).
+
+```js
+const flattenDepth = (arr, depth = 1) =>
+ depth != 1 ? arr.reduce((a, v) => a.concat(Array.isArray(v) ? flattenDepth(v, depth - 1) : v), [])
+ : arr.reduce((a, v) => a.concat(v), []);
+// flattenDepth([1,[2],[[[3],4],5]], 2) -> [1,2,[3],4,5]
+```
+
+[⬆ back to top](#table-of-contents)
+
+### groupBy
+
+Groups the element of an array based on the given function.
+
+Use `Array.map()` to map the values of an array to a function or property name.
+Use `Array.reduce()` to create an object, where the keys are produced from the mapped results.
+
+```js
+const groupBy = (arr, func) =>
+ arr.map(typeof func === 'function' ? func : val => val[func])
+ .reduce((acc, val, i) => { acc[val] = (acc[val] || []).concat(arr[i]); return acc; }, {});
+// groupBy([6.1, 4.2, 6.3], Math.floor) -> {4: [4.2], 6: [6.1, 6.3]}
+// groupBy(['one', 'two', 'three'], 'length') -> {3: ['one', 'two'], 5: ['three']}
+```
+
+[⬆ back to top](#table-of-contents)
+
+### head
+
+Returns the head of a list.
+
+Use `arr[0]` to return the first element of the passed array.
+
+```js
+const head = arr => arr[0];
+// head([1,2,3]) -> 1
+```
+
+[⬆ back to top](#table-of-contents)
+
+### initial
+
+Returns all the elements of an array except the last one.
+
+Use `arr.slice(0,-1)`to return all but the last element of the array.
+
+```js
+const initial = arr => arr.slice(0, -1);
+// initial([1,2,3]) -> [1,2]
+```
+
+[⬆ back to top](#table-of-contents)
+
+### initializeArrayWithRange
+
+Initialized an array containing the numbers in the specified range.
+
+Use `Array(end-start)` to create an array of the desired length, `Array.map()` to fill with the desired values in a range.
+You can omit `start` to use a default value of `0`.
+
+```js
+const initializeArrayWithRange = (end, start = 0) =>
+ Array.from({ length: end - start }).map((v, i) => i + start);
+// initializeArrayRange(5) -> [0,1,2,3,4]
+```
+
+[⬆ back to top](#table-of-contents)
+
+### initializeArrayWithValues
+
+Initializes and fills an array with the specified values.
+
+Use `Array(n)` to create an array of the desired length, `fill(v)` to fill it with the desired values.
+You can omit `value` to use a default value of `0`.
+
+```js
+const initializeArrayWithValues = (n, value = 0) => Array(n).fill(value);
+// initializeArray(5, 2) -> [2,2,2,2,2]
+```
+
+[⬆ back to top](#table-of-contents)
+
+### intersection
+
+Returns a list of elements that exist in both arrays.
Create a `Set` from `b`, then use `Array.filter()` on `a` to only keep values contained in `b`.
@@ -156,9 +402,54 @@ const intersection = (a, b) => { const s = new Set(b); return a.filter(x => s.ha
[⬆ back to top](#table-of-contents)
-### Array pull (mutates array)
+### last
-Use `Array.filter()` and `Array.includes()` to pull out the values that are not needed.
+Returns the last element in an array.
+
+Use `arr.length - 1` to compute index of the last element of the given array and returning it.
+
+```js
+const last = arr => arr[arr.length - 1];
+// last([1,2,3]) -> 3
+```
+
+[⬆ back to top](#table-of-contents)
+
+### nthElement
+
+Returns the nth element of an array.
+
+Use `Array.slice()` to get an array containing the nth element at the first place.
+If the index is out of bounds, return `[]`.
+Omit the second argument, `n`, to get the first element of the array.
+
+```js
+const nthElement = (arr, n=0) => (n>0? arr.slice(n,n+1) : arr.slice(n))[0];
+// nth(['a','b','c'],1) -> 'b'
+// nth(['a','b','b']-2) -> 'a'
+```
+
+[⬆ back to top](#table-of-contents)
+
+### pick
+
+Picks the key-value pairs corresponding to the given keys from an object.
+
+Use `Array.reduce()` to convert the filtered/picked keys back to a object with the corresponding key-value pair if the key exist in the obj.
+
+```js
+const pick = (obj, arr) =>
+ arr.reduce((acc, curr) => (curr in obj && (acc[curr] = obj[curr]), acc), {});
+// pick({ 'a': 1, 'b': '2', 'c': 3 }, ['a', 'c']) -> { 'a': 1, 'c': 3 }
+```
+
+[⬆ back to top](#table-of-contents)
+
+### pull
+
+Mutates the original array to filter out the values specified.
+
+Use `Array.filter()` and `Array.includes()` to pull out the values that are not needed.
Use `Array.length = 0` to mutate the passed in array by resetting it's length to zero and `Array.push()` to re-populate it with only the pulled values.
```js
@@ -173,7 +464,9 @@ const pull = (arr, ...args) => {
[⬆ back to top](#table-of-contents)
-### Array remove
+### remove
+
+Removes elements from an array for which the given function returns `false`.
Use `Array.filter()` to find array elements that return truthy values and `Array.reduce()` to remove elements using `Array.splice()`.
The `func` is invoked with three arguments (`value, index, array`).
@@ -189,7 +482,9 @@ const remove = (arr, func) =>
[⬆ back to top](#table-of-contents)
-### Array sample
+### sample
+
+Returns a random element from an array.
Use `Math.random()` to generate a random number, multiply it with `length` and round it of to the nearest whole number using `Math.floor()`.
This method also works with strings.
@@ -201,7 +496,35 @@ const sample = arr => arr[Math.floor(Math.random() * arr.length)];
[⬆ back to top](#table-of-contents)
-### Array symmetric difference
+### shuffle
+
+Randomizes the order of the values of an array.
+
+Use `Array.sort()` to reorder elements, using `Math.random()` in the comparator.
+
+```js
+const shuffle = arr => arr.sort(() => Math.random() - 0.5);
+// shuffle([1,2,3]) -> [2,3,1]
+```
+
+[⬆ back to top](#table-of-contents)
+
+### similarity
+
+Returns an array of elements that appear in both arrays.
+
+Use `filter()` to remove values that are not part of `values`, determined using `includes()`.
+
+```js
+const similarity = (arr, values) => arr.filter(v => values.includes(v));
+// similarity([1,2,3], [1,2,4]) -> [1,2]
+```
+
+[⬆ back to top](#table-of-contents)
+
+### symmetricDifference
+
+Returns the symmetric difference between two arrays.
Create a `Set` from each array, then use `Array.filter()` on each of them to only keep values not contained in the other.
@@ -215,7 +538,51 @@ const symmetricDifference = (a, b) => {
[⬆ back to top](#table-of-contents)
-### Array union
+### tail
+
+Returns all elements in an array except for the first one.
+
+Return `arr.slice(1)` if the array's `length` is more than `1`, otherwise return the whole array.
+
+```js
+const tail = arr => arr.length > 1 ? arr.slice(1) : arr;
+// tail([1,2,3]) -> [2,3]
+// tail([1]) -> [1]
+```
+
+[⬆ back to top](#table-of-contents)
+
+### take
+
+Returns an array with n elements removed from the beggining.
+
+Use `Array.slice()` to create a slice of the array with `n` elements taken from the beginning.
+
+```js
+const take = (arr, n = 1) => arr.slice(0, n);
+// take([1, 2, 3], 5) -> [1, 2, 3]
+// take([1, 2, 3], 0) -> []
+```
+
+[⬆ back to top](#table-of-contents)
+
+### takeRight
+
+Returns an array with n elements removed from the end.
+
+Use `Array.slice()` to create a slice of the array with `n` elements taken from the end.
+
+```js
+const takeRight = (arr, n = 1) => arr.slice(arr.length - n, arr.length);
+// takeRight([1, 2, 3], 2) -> [ 2, 3 ]
+// takeRight([1, 2, 3]) -> [3]
+```
+
+[⬆ back to top](#table-of-contents)
+
+### union
+
+Returns every element that exists in any of the two arrays once.
Create a `Set` with all values of `a` and `b` and convert to an array.
@@ -226,19 +593,22 @@ const union = (a, b) => Array.from(new Set([...a, ...b]));
[⬆ back to top](#table-of-contents)
-### Array without
+### without
+
+Filters out the elements of an array, that have one of the specified values.
Use `Array.filter()` to create an array excluding(using `!Array.includes()`) all given values.
```js
const without = (arr, ...args) => arr.filter(v => !args.includes(v));
// without([2, 1, 2, 3], 1, 2) -> [3]
-// without([2, 1, 2, 3, 4, 5, 5, 5, 3, 2, 7, 7], 3, 1, 5, 2) -> [ 4, 7, 7 ]
```
[⬆ back to top](#table-of-contents)
-### Array zip
+### zip
+
+Creates an array of elements, grouped based on the position in the original arrays.
Use `Math.max.apply()` to get the longest array in the arguments.
Creates an array with that length as return value and use `Array.from()` with a map-function to create an array of grouped elements.
@@ -255,352 +625,12 @@ const zip = (...arrays) => {
//zip(['a'], [1, 2], [true, false]); -> [['a', 1, true], [undefined, 2, false]]
```
-[⬆ back to top](#table-of-contents)
-
-### Average of array of numbers
-
-Use `Array.reduce()` to add each value to an accumulator, initialized with a value of `0`, divide by the `length` of the array.
-
-```js
-const average = arr => arr.reduce((acc, val) => acc + val, 0) / arr.length;
-// average([1,2,3]) -> 2
-```
-
-[⬆ back to top](#table-of-contents)
-
-### Chunk array
-
-Use `Array.from()` to create a new array, that fits the number of chunks that will be produced.
-Use `Array.slice()` to map each element of the new array to a chunk the length of `size`.
-If the original array can't be split evenly, the final chunk will contain the remaining elements.
-
-```js
-const chunk = (arr, size) =>
- Array.from({length: Math.ceil(arr.length / size)}, (v, i) => arr.slice(i * size, i * size + size));
-// chunk([1,2,3,4,5], 2) -> [[1,2],[3,4],[5]]
-```
-
-[⬆ back to top](#table-of-contents)
-
-### Compact
-
-Use `Array.filter()` to filter out falsey values (`false`, `null`, `0`, `""`, `undefined`, and `NaN`).
-
-```js
-const compact = (arr) => arr.filter(Boolean);
-// compact([0, 1, false, 2, '', 3, 'a', 'e'*23, NaN, 's', 34]) -> [ 1, 2, 3, 'a', 's', 34 ]
-```
-
-[⬆ back to top](#table-of-contents)
-
-### Count occurrences of a value in array
-
-Use `Array.reduce()` to increment a counter each time you encounter the specific value inside the array.
-
-```js
-const countOccurrences = (arr, value) => arr.reduce((a, v) => v === value ? a + 1 : a + 0, 0);
-// countOccurrences([1,1,2,1,2,3], 1) -> 3
-```
-
-[⬆ back to top](#table-of-contents)
-
-### Deep flatten array
-
-Use recursion.
-Use `Array.concat()` with an empty array (`[]`) and the spread operator (`...`) to flatten an array.
-Recursively flatten each element that is an array.
-
-```js
-const deepFlatten = arr => [].concat(...arr.map(v => Array.isArray(v) ? deepFlatten(v) : v));
-// deepFlatten([1,[2],[[3],4],5]) -> [1,2,3,4,5]
-```
-
-[⬆ back to top](#table-of-contents)
-
-### Drop elements in array
-
-Loop through the array, using `Array.shift()` to drop the first element of the array until the returned value from the function is `true`.
-Returns the remaining elements.
-
-```js
-const dropElements = (arr, func) => {
- while (arr.length > 0 && !func(arr[0])) arr.shift();
- return arr;
-};
-// dropElements([1, 2, 3, 4], n => n >= 3) -> [3,4]
-```
-
-[⬆ back to top](#table-of-contents)
-
-### Filter out non-unique values in an array
-
-Use `Array.filter()` for an array containing only the unique values.
-
-```js
-const filterNonUnique = arr => arr.filter(i => arr.indexOf(i) === arr.lastIndexOf(i));
-// filterNonUnique([1,2,2,3,4,4,5]) -> [1,3,5]
-```
-
-[⬆ back to top](#table-of-contents)
-
-### Flatten array up to depth
-
-Use recursion, decrementing `depth` by 1 for each level of depth.
-Use `Array.reduce()` and `Array.concat()` to merge elements or arrays.
-Base case, for `depth` equal to `1` stops recursion.
-Omit the second element, `depth` to flatten only to a depth of `1` (single flatten).
-
-```js
-const flattenDepth = (arr, depth = 1) =>
- depth != 1 ? arr.reduce((a, v) => a.concat(Array.isArray(v) ? flattenDepth(v, depth - 1) : v), [])
- : arr.reduce((a, v) => a.concat(v), []);
-// flattenDepth([1,[2],[[[3],4],5]], 2) -> [1,2,[3],4,5]
-```
-
-[⬆ back to top](#table-of-contents)
-
-### Flatten array
-
-Use `Array.reduce()` to get all elements inside the array and `concat()` to flatten them.
-
-```js
-const flatten = arr => arr.reduce((a, v) => a.concat(v), []);
-// flatten([1,[2],3,4]) -> [1,2,3,4]
-```
-
-[⬆ back to top](#table-of-contents)
-
-### Get max value from array
-
-Use `Math.max()` combined with the spread operator (`...`) to get the maximum value in the array.
-
-```js
-const arrayMax = arr => Math.max(...arr);
-// arrayMax([10, 1, 5]) -> 10
-```
-
-[⬆ back to top](#table-of-contents)
-
-### Get min value from array
-
-Use `Math.min()` combined with the spread operator (`...`) to get the minimum value in the array.
-
-```js
-const arrayMin = arr => Math.min(...arr);
-// arrayMin([10, 1, 5]) -> 1
-```
-
-[⬆ back to top](#table-of-contents)
-
-### Group by
-
-Use `Array.map()` to map the values of an array to a function or property name.
-Use `Array.reduce()` to create an object, where the keys are produced from the mapped results.
-
-```js
-const groupBy = (arr, func) =>
- arr.map(typeof func === 'function' ? func : val => val[func])
- .reduce((acc, val, i) => { acc[val] = (acc[val] || []).concat(arr[i]); return acc; }, {});
-// groupBy([6.1, 4.2, 6.3], Math.floor) -> {4: [4.2], 6: [6.1, 6.3]}
-// groupBy(['one', 'two', 'three'], 'length') -> {3: ['one', 'two'], 5: ['three']}
-```
-
-[⬆ back to top](#table-of-contents)
-
-### Head of list
-
-Use `arr[0]` to return the first element of the passed array.
-
-```js
-const head = arr => arr[0];
-// head([1,2,3]) -> 1
-```
-
-[⬆ back to top](#table-of-contents)
-
-### Initial of list
-
-Use `arr.slice(0,-1)`to return all but the last element of the array.
-
-```js
-const initial = arr => arr.slice(0, -1);
-// initial([1,2,3]) -> [1,2]
-```
-
-[⬆ back to top](#table-of-contents)
-
-### Initialize array with range
-
-Use `Array(end-start)` to create an array of the desired length, `Array.map()` to fill with the desired values in a range.
-You can omit `start` to use a default value of `0`.
-
-```js
-const initializeArrayRange = (end, start = 0) =>
- Array.from({ length: end - start }).map((v, i) => i + start);
-// initializeArrayRange(5) -> [0,1,2,3,4]
-```
-
-[⬆ back to top](#table-of-contents)
-
-### Initialize array with values
-
-Use `Array(n)` to create an array of the desired length, `fill(v)` to fill it with the desired values.
-You can omit `value` to use a default value of `0`.
-
-```js
-const initializeArray = (n, value = 0) => Array(n).fill(value);
-// initializeArray(5, 2) -> [2,2,2,2,2]
-```
-
-[⬆ back to top](#table-of-contents)
-
-### Last of list
-
-Use `arr.length - 1` to compute index of the last element of the given array and returning it.
-
-```js
-const last = arr => arr[arr.length - 1];
-// last([1,2,3]) -> 3
-```
-
-[⬆ back to top](#table-of-contents)
-
-### Median of array of numbers
-
-Find the middle of the array, use `Array.sort()` to sort the values.
-Return the number at the midpoint if `length` is odd, otherwise the average of the two middle numbers.
-
-```js
-const median = arr => {
- const mid = Math.floor(arr.length / 2), nums = arr.sort((a, b) => a - b);
- return arr.length % 2 !== 0 ? nums[mid] : (nums[mid - 1] + nums[mid]) / 2;
-};
-// median([5,6,50,1,-5]) -> 5
-// median([0,10,-2,7]) -> 3.5
-```
-
-[⬆ back to top](#table-of-contents)
-
-### Nth element of array
-
-Use `Array.slice()` to get an array containing the nth element at the first place.
-If the index is out of bounds, return `[]`.
-Omit the second argument, `n`, to get the first element of the array.
-
-```js
-const nth = (arr, n=0) => (n>0? arr.slice(n,n+1) : arr.slice(n))[0];
-// nth(['a','b','c'],1) -> 'b'
-// nth(['a','b','b']-2) -> 'a'
-```
-
-[⬆ back to top](#table-of-contents)
-
-### Pick
-
-Use `Array.reduce()` to convert the filtered/picked keys back to a object with the corresponding key:value pair if the key exist in the obj.
-
-```js
-const pick = (obj, arr) =>
- arr.reduce((acc, curr) => (curr in obj && (acc[curr] = obj[curr]), acc), {});
-// pick({ 'a': 1, 'b': '2', 'c': 3 }, ['a', 'c']) -> { 'a': 1, 'c': 3 }
-// pick(object, ['a', 'c'])['a'] -> 1
-```
-
-[⬆ back to top](#table-of-contents)
-
-### Shuffle array
-
-Use `Array.sort()` to reorder elements, using `Math.random()` in the comparator.
-
-```js
-const shuffle = arr => arr.sort(() => Math.random() - 0.5);
-// shuffle([1,2,3]) -> [2,3,1]
-```
-
-[⬆ back to top](#table-of-contents)
-
-### Similarity between arrays
-
-Use `filter()` to remove values that are not part of `values`, determined using `includes()`.
-
-```js
-const similarity = (arr, values) => arr.filter(v => values.includes(v));
-// similarity([1,2,3], [1,2,4]) -> [1,2]
-```
-
-[⬆ back to top](#table-of-contents)
-
-### Sum of array of numbers
-
-Use `Array.reduce()` to add each value to an accumulator, initialized with a value of `0`.
-
-```js
-const sum = arr => arr.reduce((acc, val) => acc + val, 0);
-// sum([1,2,3,4]) -> 10
-```
-
-[⬆ back to top](#table-of-contents)
-
-### Tail of list
-
-Return `arr.slice(1)` if the array's `length` is more than `1`, otherwise return the whole array.
-
-```js
-const tail = arr => arr.length > 1 ? arr.slice(1) : arr;
-// tail([1,2,3]) -> [2,3]
-// tail([1]) -> [1]
-```
-
-[⬆ back to top](#table-of-contents)
-
-### Take every nth element
-
-Use `Array.filter()` to create a new array that contains every nth element of a given array.
-
-```js
-const everynth = (arr, nth) => arr.filter((e, i) => i % nth === 0);
-// everynth([1,2,3,4,5,6], 2) -> [ 1, 3, 5 ]
-```
-
-[⬆ back to top](#table-of-contents)
-
-### Take right
-
-Use `Array.slice()` to create a slice of the array with `n` elements taken from the end.
-
-```js
-const takeRight = (arr, n = 1) => arr.slice(arr.length - n, arr.length);
-// takeRight([1, 2, 3], 2) -> [ 2, 3 ]
-// takeRight([1, 2, 3]) -> [3]
-```
-
-[⬆ back to top](#table-of-contents)
-
-### Take
-
-Use `Array.slice()` to create a slice of the array with `n` elements taken from the beginning.
-
-```js
-const take = (arr, n = 1) => arr.slice(0, n);
-// take([1, 2, 3], 5) -> [1, 2, 3]
-// take([1, 2, 3], 0) -> []
-```
-
-[⬆ back to top](#table-of-contents)
-
-### Unique values of array
-
-Use ES6 `Set` and the `...rest` operator to discard all duplicated values.
-
-```js
-const unique = arr => [...new Set(arr)];
-// unique([1,2,2,3,4,4,5]) -> [1,2,3,4,5]
-```
-
[⬆ back to top](#table-of-contents)
## Browser
-### Bottom visible
+### bottomVisible
+
+Returns `true` if the bottom of the page is visible, `false` otherwise.
Use `scrollY`, `scrollHeight` and `clientHeight` to determine if the bottom of the page is visible.
@@ -612,18 +642,22 @@ const bottomVisible = () =>
[⬆ back to top](#table-of-contents)
-### Current URL
+### currentURL
+
+Returns the current URL.
Use `window.location.href` to get current URL.
```js
-const currentUrl = () => window.location.href;
+const currentURL = () => window.location.href;
// currentUrl() -> 'https://google.com'
```
[⬆ back to top](#table-of-contents)
-### Element is visible in viewport
+### elementIsVisibleInViewport
+
+Returns `true` if the element specified is visible in the viewport, `false` otherwise.
Use `Element.getBoundingClientRect()` and the `window.inner(Width|Height)` values
to determine if a given element is visible in the viewport.
@@ -645,13 +679,15 @@ const elementIsVisibleInViewport = (el, partiallyVisible = false) => {
[⬆ back to top](#table-of-contents)
-### Get scroll position
+### getScrollPosition
+
+Returns the scroll position of the current page.
Use `pageXOffset` and `pageYOffset` if they are defined, otherwise `scrollLeft` and `scrollTop`.
You can omit `el` to use a default value of `window`.
```js
-const getScrollPos = (el = window) =>
+const getScrollPosition = (el = window) =>
({x: (el.pageXOffset !== undefined) ? el.pageXOffset : el.scrollLeft,
y: (el.pageYOffset !== undefined) ? el.pageYOffset : el.scrollTop});
// getScrollPos() -> {x: 0, y: 200}
@@ -659,7 +695,26 @@ const getScrollPos = (el = window) =>
[⬆ back to top](#table-of-contents)
-### Redirect to URL
+### getURLParameters
+
+Returns an object containing the parameters of the current URL.
+
+Use `match()` with an appropriate regular expression to get all key-value pairs, `Array.reduce()` to map and combine them into a single object.
+Pass `location.search` as the argument to apply to the current `url`.
+
+```js
+const getURLParameters = url =>
+ url.match(/([^?=&]+)(=([^&]*))/g).reduce(
+ (a, v) => (a[v.slice(0, v.indexOf('='))] = v.slice(v.indexOf('=') + 1), a), {}
+ );
+// getUrlParameters('http://url.com/page?name=Adam&surname=Smith') -> {name: 'Adam', surname: 'Smith'}
+```
+
+[⬆ back to top](#table-of-contents)
+
+### redirect
+
+Redirects to a specified URL.
Use `window.location.href` or `window.location.replace()` to redirect to `url`.
Pass a second argument to simulate a link click (`true` - default) or an HTTP redirect (`false`).
@@ -672,7 +727,9 @@ const redirect = (url, asLink = true) =>
[⬆ back to top](#table-of-contents)
-### Scroll to top
+### scrollToTop
+
+Smooth-scrolls to the top of the page.
Get distance from top using `document.documentElement.scrollTop` or `document.body.scrollTop`.
Scroll by a fraction of the distance from top. Use `window.requestAnimationFrame()` to animate the scrolling.
@@ -691,7 +748,38 @@ const scrollToTop = () => {
[⬆ back to top](#table-of-contents)
## Date
-### Convert to English date
+### getDaysDiffBetweenDates
+
+Returns the difference (in days) between two dates.
+
+Calculate the difference (in days) between to `Date` objects.
+
+```js
+const getDaysDiffBetweenDates = (dateInitial, dateFinal) => (dateFinal - dateInitial) / (1000 * 3600 * 24);
+// getDaysDiffBetweenDates(new Date("2017-12-13"), new Date("2017-12-22")) -> 9
+```
+
+[⬆ back to top](#table-of-contents)
+
+### JSONToDate
+
+Converts a JSON object to a date.
+
+Use `Date()`, to convert dates in JSON format to readable format (`dd/mm/yyyy`).
+
+```js
+const JSONToDate = arr => {
+ const dt = new Date(parseInt(arr.toString().substr(6)));
+ return `${ dt.getDate() }/${ dt.getMonth() + 1 }/${ dt.getFullYear() }`
+};
+// jsonToDate(/Date(1489525200000)/) -> "14/3/2017"
+```
+
+[⬆ back to top](#table-of-contents)
+
+### toEnglishDate
+
+Converts a date from American format to English format.
Use `Date.toISOString()`, `split('T')` and `replace()` to convert a date from American format to English format.
Throws an error if the passed time cannot be converted to a date.
@@ -702,35 +790,12 @@ const toEnglishDate = (time) =>
// toEnglishDate('09/21/2010') -> '21/09/2010'
```
-[⬆ back to top](#table-of-contents)
-
-### Get days difference between dates
-
-Calculate the difference (in days) between to `Date` objects.
-
-```js
-const getDaysDiffBetweenDates = (dateInitial, dateFinal) => (dateFinal - dateInitial) / (1000 * 3600 * 24);
-// getDaysDiffBetweenDates(new Date("2017-12-13"), new Date("2017-12-22")) -> 9
-```
-
-[⬆ back to top](#table-of-contents)
-
-### JSON to date
-
-Use `Date()`, to convert dates in JSON format to readable format (`dd/mm/yyyy`).
-
-```js
-const jsonToDate = arr => {
- const dt = new Date(parseInt(arr.toString().substr(6)));
- return `${ dt.getDate() }/${ dt.getMonth() + 1 }/${ dt.getFullYear() }`
-};
-// jsonToDate(/Date(1489525200000)/) -> "14/3/2017"
-```
-
[⬆ back to top](#table-of-contents)
## Function
-### Chain asynchronous functions
+### chainAsync
+
+Chains asynchronous functions.
Loop through an array of functions containing asynchronous events, calling `next` when each asynchronous event has completed.
@@ -747,7 +812,9 @@ chainAsync([
[⬆ back to top](#table-of-contents)
-### Compose functions
+### compose
+
+Performs right-to-left function composition.
Use `Array.reduce()` to perform right-to-left function composition.
The last (rightmost) function can accept one or more arguments; the remaining functions must be unary.
@@ -764,7 +831,9 @@ multiplyAndAdd5(5, 2) -> 15
[⬆ back to top](#table-of-contents)
-### Curry
+### curry
+
+Curries a function.
Use recursion.
If the number of provided arguments (`args`) is sufficient, call the passed function `f`.
@@ -782,7 +851,9 @@ const curry = (fn, arity = fn.length, ...args) =>
[⬆ back to top](#table-of-contents)
-### Log function name
+### functionName
+
+Logs the name of a function.
Use `console.debug()` and the `name` property of the passed method to log the method's name to the `debug` channel of the console.
@@ -793,13 +864,15 @@ const functionName = fn => (console.debug(fn.name), fn);
[⬆ back to top](#table-of-contents)
-### Pipe functions
+### pipe
+
+Performs left-to-right function composition.
Use `Array.reduce()` with the spread operator (`...`) to perform left-to-right function composition.
The first (leftmost) function can accept one or more arguments; the remaining functions must be unary.
```js
-const pipe = (...fns) => fns.reduce((f, g) => (...args) => g(f(...args)));
+const pipeFunctions = (...fns) => fns.reduce((f, g) => (...args) => g(f(...args)));
/*
const add5 = x => x + 5
const multiply = (x, y) => x * y
@@ -810,10 +883,12 @@ multiplyAndAdd5(5, 2) -> 15
[⬆ back to top](#table-of-contents)
-### Promisify
+### promisify
-Use currying to return a function returning a `Promise` that calls the original function.
-Use the `...rest` operator to pass in all the parameters.
+Converts an asynchronous function to return a promise.
+
+Use currying to return a function returning a `Promise` that calls the original function.
+Use the `...rest` operator to pass in all the parameters.
*In Node 8+, you can use [`util.promisify`](https://nodejs.org/api/util.html#util_util_promisify_original)*
@@ -830,19 +905,23 @@ const promisify = func =>
[⬆ back to top](#table-of-contents)
-### Run promises in series
+### runPromisesInSeries
-Run an array of promises in series using `Array.reduce()` by creating a promise chain, where each promise returns the next promise when resolved.
+Runs an array of promises in series.
+
+Use `Array.reduce()` to create a promise chain, where each promise returns the next promise when resolved.
```js
-const series = ps => ps.reduce((p, next) => p.then(next), Promise.resolve());
+const runPromisesInSeries = ps => ps.reduce((p, next) => p.then(next), Promise.resolve());
// const delay = (d) => new Promise(r => setTimeout(r, d))
// series([() => delay(1000), () => delay(2000)]) -> executes each promise sequentially, taking a total of 3 seconds to complete
```
[⬆ back to top](#table-of-contents)
-### Sleep
+### sleep
+
+Delays the execution of an asynchronous function.
Delay executing part of an `async` function, by putting it to sleep, returning a `Promise`.
@@ -860,7 +939,35 @@ async function sleepyWork() {
[⬆ back to top](#table-of-contents)
## Math
-### Collatz algorithm
+### arrayAverage
+
+Returns the average of an array of numbers.
+
+Use `Array.reduce()` to add each value to an accumulator, initialized with a value of `0`, divide by the `length` of the array.
+
+```js
+const arrayAverage = arr => arr.reduce((acc, val) => acc + val, 0) / arr.length;
+// average([1,2,3]) -> 2
+```
+
+[⬆ back to top](#table-of-contents)
+
+### arraySum
+
+Returns the sum of an array of numbers.
+
+Use `Array.reduce()` to add each value to an accumulator, initialized with a value of `0`.
+
+```js
+const arraySum = arr => arr.reduce((acc, val) => acc + val, 0);
+// sum([1,2,3,4]) -> 10
+```
+
+[⬆ back to top](#table-of-contents)
+
+### collatz
+
+Applies the Collatz algorithm.
If `n` is even, return `n/2`. Otherwise return `3n+1`.
@@ -872,7 +979,23 @@ const collatz = n => (n % 2 == 0) ? (n / 2) : (3 * n + 1);
[⬆ back to top](#table-of-contents)
-### Distance between two points
+### digitize
+
+Converts a number to an array of digits.
+
+Convert the number to a string, using spread operators in ES6(`[...string]`) build an array.
+Use `Array.map()` and `parseInt()` to transform each value to an integer.
+
+```js
+const digitize = n => [...''+n].map(i => parseInt(i));
+// digitize(2334) -> [2, 3, 3, 4]
+```
+
+[⬆ back to top](#table-of-contents)
+
+### distance
+
+Returns the distance between two points.
Use `Math.hypot()` to calculate the Euclidean distance between two points.
@@ -883,30 +1006,9 @@ const distance = (x0, y0, x1, y1) => Math.hypot(x1 - x0, y1 - y0);
[⬆ back to top](#table-of-contents)
-### Divisible by number
+### factorial
-Use the modulo operator (`%`) to check if the remainder is equal to `0`.
-
-```js
-const isDivisible = (dividend, divisor) => dividend % divisor === 0;
-// isDivisible(6,3) -> true
-```
-
-[⬆ back to top](#table-of-contents)
-
-### Even or odd number
-
-Checks whether a number is odd or even using the modulo (`%`) operator.
-Returns `true` if the number is even, `false` if the number is odd.
-
-```js
-const isEven = num => num % 2 === 0;
-// isEven(3) -> false
-```
-
-[⬆ back to top](#table-of-contents)
-
-### Factorial
+Calculates the factorial of a number.
Use recursion.
If `n` is less than or equal to `1`, return `1`.
@@ -922,7 +1024,9 @@ const factorial = n =>
[⬆ back to top](#table-of-contents)
-### Fibonacci array generator
+### fibonacci
+
+Generates an array, containing the Fibonacci sequence, up until the nth term.
Create an empty array of the specific length, initializing the first two values (`0` and `1`).
Use `Array.reduce()` to add values into the array, using the sum of the last two values, except for the first two.
@@ -935,7 +1039,9 @@ const fibonacci = n =>
[⬆ back to top](#table-of-contents)
-### Greatest common divisor (GCD)
+### gcd
+
+Calculates the greatest common divisor between two numbers.
Use recursion.
Base case is when `y` equals `0`. In this case, return `x`.
@@ -948,7 +1054,9 @@ const gcd = (x, y) => !y ? x : gcd(y, x % y);
[⬆ back to top](#table-of-contents)
-### Hamming distance
+### hammingDistance
+
+Calculates the Hamming distance between two values.
Use XOR operator (`^`) to find the bit difference between the two numbers, convert to binary string using `toString(2)`.
Count and return the number of `1`s in the string, using `match(/1/g)`.
@@ -961,7 +1069,36 @@ const hammingDistance = (num1, num2) =>
[⬆ back to top](#table-of-contents)
-### Least common multiple (LCM)
+### isDivisible
+
+Checks if the first numeric argument is divisible by the second one.
+
+Use the modulo operator (`%`) to check if the remainder is equal to `0`.
+
+```js
+const isDivisible = (dividend, divisor) => dividend % divisor === 0;
+// isDivisible(6,3) -> true
+```
+
+[⬆ back to top](#table-of-contents)
+
+### isEven
+
+Returns `true` if the given number is even, `false` otherwise.
+
+Checks whether a number is odd or even using the modulo (`%`) operator.
+Returns `true` if the number is even, `false` if the number is odd.
+
+```js
+const isEven = num => num % 2 === 0;
+// isEven(3) -> false
+```
+
+[⬆ back to top](#table-of-contents)
+
+### lcm
+
+Returns the least common multiple of two numbers.
Use the greatest common divisor (GCD) formula and `Math.abs()` to determine the least common multiple.
The GCD formula uses recursion.
@@ -976,20 +1113,58 @@ const lcm = (x,y) => {
[⬆ back to top](#table-of-contents)
-### Percentile
+### median
-Use `Array.reduce()` to calculate how many numbers are below the value and how many are the same value and
-apply the percentile formula.
+Returns the median of an array of numbers.
+
+Find the middle of the array, use `Array.sort()` to sort the values.
+Return the number at the midpoint if `length` is odd, otherwise the average of the two middle numbers.
```js
-const percentile = (arr, val) =>
+const median = arr => {
+ const mid = Math.floor(arr.length / 2), nums = arr.sort((a, b) => a - b);
+ return arr.length % 2 !== 0 ? nums[mid] : (nums[mid - 1] + nums[mid]) / 2;
+};
+// median([5,6,50,1,-5]) -> 5
+// median([0,10,-2,7]) -> 3.5
+```
+
+[⬆ back to top](#table-of-contents)
+
+### palindrome
+
+Returns `true` if the given string is a palindrome, `false` otherwise.
+
+Convert string `toLowerCase()` and use `replace()` to remove non-alphanumeric characters from it.
+Then, `split('')` into individual characters, `reverse()`, `join('')` and compare to the original, unreversed string, after converting it `tolowerCase()`.
+
+```js
+const palindrome = str => {
+ const s = str.toLowerCase().replace(/[\W_]/g,'');
+ return s === s.split('').reverse().join('');
+}
+// palindrome('taco cat') -> true
+ ```
+
+[⬆ back to top](#table-of-contents)
+
+### percentile
+
+Uses the percentile formula to calculate how many numbers in the given array are less or equal to the given value.
+
+Use `Array.reduce()` to calculate how many numbers are below the value and how many are the same value and apply the percentile formula.
+
+```js
+const percentile = (arr, val) =>
100 * arr.reduce((acc,v) => acc + (v < val ? 1 : 0) + (v === val ? 0.5 : 0), 0) / arr.length;
// percentile([1,2,3,4,5,6,7,8,9,10], 6) -> 55
```
[⬆ back to top](#table-of-contents)
-### Powerset
+### powerset
+
+Returns the powerset of a given array of numbers.
Use `Array.reduce()` combined with `Array.map()` to iterate over elements and combine into an array containing all combinations.
@@ -1001,7 +1176,9 @@ const powerset = arr =>
[⬆ back to top](#table-of-contents)
-### Random integer in range
+### randomIntegerInRange
+
+Returns a random integer in the specified range.
Use `Math.random()` to generate a random number and map it to the desired range, using `Math.floor()` to make it an integer.
@@ -1012,18 +1189,22 @@ const randomIntegerInRange = (min, max) => Math.floor(Math.random() * (max - min
[⬆ back to top](#table-of-contents)
-### Random number in range
+### randomNumberInRange
+
+Returns a random number in the specified range.
Use `Math.random()` to generate a random value, map it to the desired range using multiplication.
```js
-const randomInRange = (min, max) => Math.random() * (max - min) + min;
+const randomNumberInRange = (min, max) => Math.random() * (max - min) + min;
// randomInRange(2,10) -> 6.0211363285087005
```
[⬆ back to top](#table-of-contents)
-### Round number to n digits
+### round
+
+Rounds a number to a specified amount of digits.
Use `Math.round()` and template literals to round the number to the specified number of digits.
Omit the second argument, `decimals` to round to an integer.
@@ -1035,7 +1216,9 @@ const round = (n, decimals=0) => Number(`${Math.round(`${n}e${decimals}`)}e-${de
[⬆ back to top](#table-of-contents)
-### Standard deviation
+### standardDeviation
+
+Returns the standard deviation of an array of numbers.
Use `Array.reduce()` to calculate the mean, variance and the sum of the variance of the values, the variance of the values, then
determine the standard deviation.
@@ -1056,7 +1239,9 @@ const standardDeviation = (arr, usePopulation = false) => {
[⬆ back to top](#table-of-contents)
## Media
-### Speech synthesis (experimental)
+### speechSynthesis
+
+Performs speech synthesis (experimental).
Use `SpeechSynthesisUtterance.voice` and `window.speechSynthesis.getVoices()` to convert a message to speech.
Use `window.speechSynthesis.speak()` to play the message.
@@ -1064,7 +1249,7 @@ Use `window.speechSynthesis.speak()` to play the message.
Learn more about the [SpeechSynthesisUtterance interface of the Web Speech API](https://developer.mozilla.org/en-US/docs/Web/API/SpeechSynthesisUtterance).
```js
-const speak = message => {
+const speechSynthesis = message => {
const msg = new SpeechSynthesisUtterance(message);
msg.voice = window.speechSynthesis.getVoices()[0];
window.speechSynthesis.speak(msg);
@@ -1075,7 +1260,23 @@ const speak = message => {
[⬆ back to top](#table-of-contents)
## Node
-### Read file as array of lines
+### JSONToFile
+
+Writes a JSON object to a file.
+
+Use `fs.writeFile()`, template literals and `JSON.stringify()` to write a `json` object to a `.json` file.
+
+```js
+const fs = require('fs');
+const JSONToFile = (obj, filename) => fs.writeFile(`${filename}.json`, JSON.stringify(obj, null, 2))
+// jsonToFile({test: "is passed"}, 'testJsonFile') -> writes the object to 'testJsonFile.json'
+```
+
+[⬆ back to top](#table-of-contents)
+
+### readFileLines
+
+Returns an array of lines from the specified file.
Use `readFileSync` function in `fs` node package to create a `Buffer` from a file.
convert buffer to string using `toString(encoding)` function.
@@ -1083,7 +1284,7 @@ creating an array from contents of file by `split`ing file content line by line(
```js
const fs = require('fs');
-const readFileToArray = filename => fs.readFileSync(filename).toString('UTF8').split('\n');
+const readFileLines = filename => fs.readFileSync(filename).toString('UTF8').split('\n');
/*
contents of test.txt :
line1
@@ -1095,22 +1296,12 @@ const readFileToArray = filename => fs.readFileSync(filename).toString('UTF8').s
*/
```
-[⬆ back to top](#table-of-contents)
-
-### Write JSON to file
-
-Use `fs.writeFile()`, template literals and `JSON.stringify()` to write a `json` object to a `.json` file.
-
-```js
-const fs = require('fs');
-const jsonToFile = (obj, filename) => fs.writeFile(`${filename}.json`, JSON.stringify(obj, null, 2))
-// jsonToFile({test: "is passed"}, 'testJsonFile') -> writes the object to 'testJsonFile.json'
-```
-
[⬆ back to top](#table-of-contents)
## Object
-### Clean JSON object
+### cleanObj
+
+Removes any properties except the ones specified from a JSON object.
Use `Object.keys()` method to loop over given json object and deleting keys that are not `include`d in given array.
also if you give it a special key(`childIndicator`) it will search deeply inside it to apply function to inner objects too.
@@ -1134,7 +1325,9 @@ const cleanObj = (obj, keysToKeep = [], childIndicator) => {
[⬆ back to top](#table-of-contents)
-### Object from key-value pairs
+### objectFromPairs
+
+Creates an object from the given key-value pairs.
Use `Array.reduce()` to create and combine key-value pairs.
@@ -1145,7 +1338,9 @@ const objectFromPairs = arr => arr.reduce((a, v) => (a[v[0]] = v[1], a), {});
[⬆ back to top](#table-of-contents)
-### Object to key-value pairs
+### objectToPairs
+
+Creates an array of key-value pair arrays from an object.
Use `Object.keys()` and `Array.map()` to iterate over the object's keys and produce an array with key-value pairs.
@@ -1156,7 +1351,9 @@ const objectToPairs = obj => Object.keys(obj).map(k => [k, obj[k]]);
[⬆ back to top](#table-of-contents)
-### Shallow clone object
+### shallowClone
+
+Creates a shallow clone of an object.
Use `Object.assign()` and an empty object (`{}`) to create a shallow clone of the original.
@@ -1172,7 +1369,9 @@ a === b -> false
[⬆ back to top](#table-of-contents)
## String
-### Anagrams of string (with duplicates)
+### anagrams
+
+Generates all anagrams of a string (contains duplicates).
Use recursion.
For each letter in the given string, create all the partial anagrams for the rest of its letters.
@@ -1190,18 +1389,9 @@ const anagrams = str => {
[⬆ back to top](#table-of-contents)
-### Capitalize first letter of every word
+### Capitalize
-Use `replace()` to match the first character of each word and `toUpperCase()` to capitalize it.
-
-```js
-const capitalizeEveryWord = str => str.replace(/\b[a-z]/g, char => char.toUpperCase());
-// capitalizeEveryWord('hello world!') -> 'Hello World!'
-```
-
-[⬆ back to top](#table-of-contents)
-
-### Capitalize first letter
+Capitalizes the first letter of a string.
Use destructuring and `toUpperCase()` to capitalize first letter, `...rest` to get array of characters after first letter and then `Array.join('')` to make it a string again.
Omit the `lowerRest` parameter to keep the rest of the string intact, or set it to `true` to convert to lower case.
@@ -1215,28 +1405,41 @@ const capitalize = ([first,...rest], lowerRest = false) =>
[⬆ back to top](#table-of-contents)
-### Check for palindrome
+### capitalizeEveryWord
-Convert string `toLowerCase()` and use `replace()` to remove non-alphanumeric characters from it.
-Then, `split('')` into individual characters, `reverse()`, `join('')` and compare to the original, unreversed string, after converting it `tolowerCase()`.
+Capitalizes the first letter of every word in a string.
+
+Use `replace()` to match the first character of each word and `toUpperCase()` to capitalize it.
```js
-const palindrome = str => {
- const s = str.toLowerCase().replace(/[\W_]/g,'');
- return s === s.split('').reverse().join('');
-}
-// palindrome('taco cat') -> true
- ```
+const capitalizeEveryWord = str => str.replace(/\b[a-z]/g, char => char.toUpperCase());
+// capitalizeEveryWord('hello world!') -> 'Hello World!'
+```
[⬆ back to top](#table-of-contents)
-### Convert string from camelcase
+### escapeRegExp
-Use `replace()` to remove underscores, hyphens and spaces and convert words to camelcase.
-Omit the scond argument to use a default separator of '_'.
+Escapes a string to use in a regular expression.
+
+Use `replace()` to escape special characters.
```js
-const fromCamelCase = (str, separator = '_') =>
+const escapeRegExp = str => str.replace(/[.*+?^${}()|[\]\\]/g, '\\$&');
+// escapeRegExp('(test)') -> \\(test\\)
+```
+
+[⬆ back to top](#table-of-contents)
+
+### fromCamelCase
+
+Converts a string from camelcase.
+
+Use `replace()` to remove underscores, hyphens and spaces and convert words to camelcase.
+Omit the scond argument to use a default separator of `_`.
+
+```js
+const fromCamelCase = (str, separator = '_') =>
str.replace(/([a-z\d])([A-Z])/g, '$1' + separator + '$2')
.replace(/([A-Z]+)([A-Z][a-z\d]+)/g, '$1' + separator + '$2').toLowerCase();
// fromCamelCase('someDatabaseFieldName', ' ') -> 'some database field name'
@@ -1246,22 +1449,9 @@ const fromCamelCase = (str, separator = '_') =>
[⬆ back to top](#table-of-contents)
-### Convert string to camelcase
+### reverseString
-Use `replace()` to remove underscores, hyphens and spaces and convert words to camelcase.
-
-```js
-const toCamelCase = str =>
- str.replace(/^([A-Z])|[\s-_]+(\w)/g, (match, p1, p2, offset) => p2 ? p2.toUpperCase() : p1.toLowerCase());
-// toCamelCase("some_database_field_name") -> 'someDatabaseFieldName'
-// toCamelCase("Some label that needs to be camelized") -> 'someLabelThatNeedsToBeCamelized'
-// toCamelCase("some-javascript-property") -> 'someJavascriptProperty'
-// toCamelCase("some-mixed_string with spaces_underscores-and-hyphens") -> 'someMixedStringWithSpacesUnderscoresAndHyphens'
-```
-
-[⬆ back to top](#table-of-contents)
-
-### Reverse a string
+Reverses a string.
Use array destructuring and `Array.reverse()` to reverse the order of the characters in the string.
Combine characters to get a string using `join('')`.
@@ -1273,7 +1463,9 @@ const reverseString = str => [...str].reverse().join('');
[⬆ back to top](#table-of-contents)
-### Sort characters in string (alphabetical)
+### sortCharactersInString
+
+Alphabetically sorts the characters in a string.
Split the string using `split('')`, `Array.sort()` utilizing `localeCompare()`, recombine using `join('')`.
@@ -1285,13 +1477,32 @@ const sortCharactersInString = str =>
[⬆ back to top](#table-of-contents)
-### Truncate a String
+### toCamelCase
+
+Converts a string to camelcase.
+
+Use `replace()` to remove underscores, hyphens and spaces and convert words to camelcase.
+
+```js
+const toCamelCase = str =>
+ str.replace(/^([A-Z])|[\s-_]+(\w)/g, (match, p1, p2, offset) => p2 ? p2.toUpperCase() : p1.toLowerCase());
+// toCamelCase("some_database_field_name") -> 'someDatabaseFieldName'
+// toCamelCase("Some label that needs to be camelized") -> 'someLabelThatNeedsToBeCamelized'
+// toCamelCase("some-javascript-property") -> 'someJavascriptProperty'
+// toCamelCase("some-mixed_string with spaces_underscores-and-hyphens") -> 'someMixedStringWithSpacesUnderscoresAndHyphens'
+```
+
+[⬆ back to top](#table-of-contents)
+
+### truncateString
+
+Truncates a string up to a specified length.
Determine if the string's `length` is greater than `num`.
Return the string truncated to the desired length, with `...` appended to the end or the original string.
```js
-const truncate = (str, num) =>
+const truncateString = (str, num) =>
str.length > num ? str.slice(0, num > 3 ? num - 3 : num) + '...' : str;
// truncate('boomerang', 7) -> 'boom...'
```
@@ -1299,31 +1510,24 @@ const truncate = (str, num) =>
[⬆ back to top](#table-of-contents)
## Utility
-### 3-digit hexcode to 6-digit hexcode
+### extendHex
-Use `Array.map()`, `split()` and `Array.join()` to join the mapped array for converting a three-digit RGB notated hexadecimal color-code to the six-digit form.
+Extends a 3-digit color code to a 6-digit color code.
+
+Use `Array.map()`, `split()` and `Array.join()` to join the mapped array for converting a 3-digit RGB notated hexadecimal color-code to the 6-digit form.
`Array.slice()` is used to remove `#` from string start since it's added once.
```js
-const convertHex = shortHex =>
- '#' + shortHex.slice(shortHex.startsWith('#') ? 1 : 0).split().map(x => x+x).join()
+const extendHex = shortHex =>
+ '#' + shortHex.slice(shortHex.startsWith('#') ? 1 : 0).split('').map(x => x+x).join('')
// convertHex('#03f') -> '#0033ff'
// convertHex('05a') -> '#0055aa'
```
[⬆ back to top](#table-of-contents)
-### Escape regular expression
+### getType
-Use `replace()` to escape special characters.
-
-```js
-const escapeRegExp = str => str.replace(/[.*+?^${}()|[\]\\]/g, '\\$&');
-// escapeRegExp('(test)') -> \\(test\\)
-```
-
-[⬆ back to top](#table-of-contents)
-
-### Get native type of value
+Returns the native type of a value.
Returns lower-cased constructor name of value, "undefined" or "null" if value is undefined or null
@@ -1335,21 +1539,29 @@ const getType = v =>
[⬆ back to top](#table-of-contents)
-### Hexcode to RGB
+### hexToRGB
-Use bitwise right-shift operator and mask bits with `&` (and) operator to convert a hexadecimal color code (prefixed with `#`) to a string with the RGB values.
+Converts a colorcode to a `rgb()` string.
+
+Use bitwise right-shift operator and mask bits with `&` (and) operator to convert a hexadecimal color code (prefixed with `#`) to a string with the RGB values. In case it's a 3-digit-colorcode, do the same with the 6-digit-colorcode extended by the extendHex() function (ref. `extendHex` snippet)
```js
const hexToRgb = hex => {
- const h = parseInt(hex.slice(1), 16);
- return `rgb(${h >> 16}, ${(h & 0x00ff00) >> 8}, ${h & 0x0000ff})`;
-}
+ const extendHex = shortHex =>
+ '#' + shortHex.slice(shortHex.startsWith('#') ? 1 : 0).split('').map(x => x+x).join('');
+ return hex.slice(1).length==3 ?
+ `rgb(${parseInt(extendHex(hex).slice(1), 16) >> 16}, ${(parseInt(extendHex(hex).slice(1), 16) & 0x00ff00) >> 8}, ${parseInt(extendHex(hex).slice(1), 16) & 0x0000ff})`:
+ `rgb(${parseInt(hex.slice(1), 16) >> 16}, ${(parseInt(hex.slice(1), 16) & 0x00ff00) >> 8}, ${parseInt(hex.slice(1), 16) & 0x0000ff})`;
+}
// hexToRgb('#27ae60') -> 'rgb(39, 174, 96)'
+// hexToRgb('#acd') -> 'rgb(170, 204, 221)'
```
[⬆ back to top](#table-of-contents)
-### Is array
+### isArray
+
+Checks if the given argument is an array.
Use `Array.isArray()` to check if a value is classified as an array.
@@ -1361,7 +1573,9 @@ const isArray = val => !!val && Array.isArray(val);
[⬆ back to top](#table-of-contents)
-### Is boolean
+### isBoolean
+
+Checks if the given argument is a native boolean element.
Use `typeof` to check if a value is classified as a boolean primitive.
@@ -1373,7 +1587,9 @@ const isBoolean = val => typeof val === 'boolean';
[⬆ back to top](#table-of-contents)
-### Is function
+### isFunction
+
+Checks if the given argument is a function.
Use `typeof` to check if a value is classified as a function primitive.
@@ -1385,7 +1601,9 @@ const isFunction = val => val && typeof val === 'function';
[⬆ back to top](#table-of-contents)
-### Is number
+### isNumber
+
+Checks if the given argument is a number.
Use `typeof` to check if a value is classified as a number primitive.
@@ -1397,7 +1615,9 @@ const isNumber = val => typeof val === 'number';
[⬆ back to top](#table-of-contents)
-### Is string
+### isString
+
+Checks if the given argument is a string.
Use `typeof` to check if a value is classified as a string primitive.
@@ -1409,7 +1629,9 @@ const isString = val => typeof val === 'string';
[⬆ back to top](#table-of-contents)
-### Is symbol
+### isSymbol
+
+Checks if the given argument is a symbol.
Use `typeof` to check if a value is classified as a symbol primitive.
@@ -1421,16 +1643,29 @@ const isSymbol = val => typeof val === 'symbol';
[⬆ back to top](#table-of-contents)
-### Measure time taken by function
+### RGBToHex
+
+Converts the values of RGB components to a colorcode.
+
+Convert given RGB parameters to hexadecimal string using bitwise left-shift operator (`<<`) and `toString(16)`, then `padStart(6,'0')` to get a 6-digit hexadecimal value.
+
+```js
+const RGBToHex = (r, g, b) => ((r << 16) + (g << 8) + b).toString(16).padStart(6, '0');
+// rgbToHex(255, 165, 1) -> 'ffa501'
+```
+
+[⬆ back to top](#table-of-contents)
+
+### timeTaken
+
+Measures the time taken by a function to execute.
Use `console.time()` and `console.timeEnd()` to measure the difference between the start and end times to determine how long the callback took to execute.
```js
const timeTaken = callback => {
- console.time('timeTaken');
- const r = callback();
- console.timeEnd('timeTaken');
- return r;
+ console.time('timeTaken'); const r = callback();
+ console.timeEnd('timeTaken'); return r;
};
// timeTaken(() => Math.pow(2, 10)) -> 1024
// (logged): timeTaken: 0.02099609375ms
@@ -1438,19 +1673,9 @@ const timeTaken = callback => {
[⬆ back to top](#table-of-contents)
-### Number to array of digits
+### toOrdinalSuffix
-Convert the number to a string, using spread operators in ES6(`[...string]`) build an array.
-Use `Array.map()` and `parseInt()` to transform each value to an integer.
-
-```js
-const digitize = n => [...''+n].map(i => parseInt(i));
-// digitize(2334) -> [2, 3, 3, 4]
-```
-
-[⬆ back to top](#table-of-contents)
-
-### Ordinal suffix of number
+Adds an ordinal suffix to a number.
Use the modulo operator (`%`) to find values of single and tens digits.
Find which ordinal pattern digits match.
@@ -1468,38 +1693,14 @@ const toOrdinalSuffix = num => {
[⬆ back to top](#table-of-contents)
-### RGB to hexadecimal
+### UUIDGenerator
-Convert given RGB parameters to hexadecimal string using bitwise left-shift operator (`<<`) and `toString(16)`, then `padStart(6,'0')` to get a 6-digit hexadecimal value.
-
-```js
-const rgbToHex = (r, g, b) => ((r << 16) + (g << 8) + b).toString(16).padStart(6, '0');
-// rgbToHex(255, 165, 1) -> 'ffa501'
-```
-
-[⬆ back to top](#table-of-contents)
-
-### URL parameters
-
-Use `match()` with an appropriate regular expression to get all key-value pairs, `Array.reduce()` to map and combine them into a single object.
-Pass `location.search` as the argument to apply to the current `url`.
-
-```js
-const getUrlParameters = url =>
- url.match(/([^?=&]+)(=([^&]*))/g).reduce(
- (a, v) => (a[v.slice(0, v.indexOf('='))] = v.slice(v.indexOf('=') + 1), a), {}
- );
-// getUrlParameters('http://url.com/page?name=Adam&surname=Smith') -> {name: 'Adam', surname: 'Smith'}
-```
-
-[⬆ back to top](#table-of-contents)
-
-### UUID generator
+Generates a UUID.
Use `crypto` API to generate a UUID, compliant with [RFC4122](https://www.ietf.org/rfc/rfc4122.txt) version 4.
```js
-const uuid = () =>
+const UUIDGenerator = () =>
([1e7] + -1e3 + -4e3 + -8e3 + -1e11).replace(/[018]/g, c =>
(c ^ crypto.getRandomValues(new Uint8Array(1))[0] & 15 >> c / 4).toString(16)
);
@@ -1508,7 +1709,9 @@ const uuid = () =>
[⬆ back to top](#table-of-contents)
-### Validate email
+### validateEmail
+
+Returns `true` if the given string is a valid email, `false` otherwise.
Use a regular expression to check if the email is valid.
Returns `true` if email is valid, `false` if not.
@@ -1521,7 +1724,9 @@ const validateEmail = str =>
[⬆ back to top](#table-of-contents)
-### Validate number
+### validateNumber
+
+Returns `true` if the given value is a number, `false` otherwise.
Use `!isNaN` in combination with `parseFloat()` to check if the argument is a number.
Use `isFinite()` to check if the number is finite.
diff --git a/docs/favicon.png b/docs/favicon.png
new file mode 100644
index 000000000..3a50a365c
Binary files /dev/null and b/docs/favicon.png differ
diff --git a/docs/index.html b/docs/index.html
new file mode 100644
index 000000000..e11294cd0
--- /dev/null
+++ b/docs/index.html
@@ -0,0 +1,1048 @@
+
+
+
+
+
+ 30 seconds of code
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
30 seconds of code
+
+
+
+
+
Array
+
arrayMax
+
Returns the maximum value in an array.
+
Use Math.max() combined with the spread operator (...) to get the maximum value in the array.
Chunks an array into smaller arrays of a specified size.
+
Use Array.from() to create a new array, that fits the number of chunks that will be produced.
+Use Array.slice() to map each element of the new array to a chunk the length of size.
+If the original array can't be split evenly, the final chunk will contain the remaining elements.
Use Array.reduce() to increment a counter each time you encounter the specific value inside the array.
+
const countOccurrences = (arr, value) => arr.reduce((a, v) => v === value ? a + 1 : a + 0, 0);
+// countOccurrences([1,1,2,1,2,3], 1) -> 3
+
+
deepFlatten
+
Deep flattens an array.
+
Use recursion.
+Use Array.concat() with an empty array ([]) and the spread operator (...) to flatten an array.
+Recursively flatten each element that is an array.
Removes elements in an array until the passed function returns true. Returns the remaining elements in the array.
+
Loop through the array, using Array.shift() to drop the first element of the array until the returned value from the function is true.
+Returns the remaining elements.
Use recursion, decrementing depth by 1 for each level of depth.
+Use Array.reduce() and Array.concat() to merge elements or arrays.
+Base case, for depth equal to 1 stops recursion.
+Omit the second element, depth to flatten only to a depth of 1 (single flatten).
Groups the element of an array based on the given function.
+
Use Array.map() to map the values of an array to a function or property name.
+Use Array.reduce() to create an object, where the keys are produced from the mapped results.
Initialized an array containing the numbers in the specified range.
+
Use Array(end-start) to create an array of the desired length, Array.map() to fill with the desired values in a range.
+You can omit start to use a default value of 0.
Use Array.slice() to get an array containing the nth element at the first place.
+If the index is out of bounds, return [].
+Omit the second argument, n, to get the first element of the array.
Mutates the original array to filter out the values specified.
+
Use Array.filter() and Array.includes() to pull out the values that are not needed.
+Use Array.length = 0 to mutate the passed in array by resetting it's length to zero and Array.push() to re-populate it with only the pulled values.
Removes elements from an array for which the given function returns false.
+
Use Array.filter() to find array elements that return truthy values and Array.reduce() to remove elements using Array.splice().
+The func is invoked with three arguments (value, index, array).
Use Math.random() to generate a random number, multiply it with length and round it of to the nearest whole number using Math.floor().
+This method also works with strings.
Creates an array of elements, grouped based on the position in the original arrays.
+
Use Math.max.apply() to get the longest array in the arguments.
+Creates an array with that length as return value and use Array.from() with a map-function to create an array of grouped elements.
+If lengths of the argument-arrays vary, undefined is used where no value could be found.
Returns true if the element specified is visible in the viewport, false otherwise.
+
Use Element.getBoundingClientRect() and the window.inner(Width|Height) values
+to determine if a given element is visible in the viewport.
+Omit the second argument to determine if the element is entirely visible, or specify true to determine if
+it is partially visible.
+
const elementIsVisibleInViewport = (el, partiallyVisible = false) => {
+ const { top, left, bottom, right } = el.getBoundingClientRect();
+ return partiallyVisible
+ ? ((top > 0 && top < innerHeight) || (bottom > 0 && bottom < innerHeight)) &&
+ ((left > 0 && left < innerWidth) || (right > 0 && right < innerWidth))
+ : top >= 0 && left >= 0 && bottom <= innerHeight && right <= innerWidth;
+};
+// e.g. 100x100 viewport and a 10x10px element at position {top: -1, left: 0, bottom: 9, right: 10}
+// elementIsVisibleInViewport(el) -> false (not fully visible)
+// elementIsVisibleInViewport(el, true) -> true (partially visible)
+
+
getScrollPosition
+
Returns the scroll position of the current page.
+
Use pageXOffset and pageYOffset if they are defined, otherwise scrollLeft and scrollTop.
+You can omit el to use a default value of window.
Returns an object containing the parameters of the current URL.
+
Use match() with an appropriate regular expression to get all key-value pairs, Array.reduce() to map and combine them into a single object.
+Pass location.search as the argument to apply to the current url.
Use window.location.href or window.location.replace() to redirect to url.
+Pass a second argument to simulate a link click (true - default) or an HTTP redirect (false).
Get distance from top using document.documentElement.scrollTop or document.body.scrollTop.
+Scroll by a fraction of the distance from top. Use window.requestAnimationFrame() to animate the scrolling.
+
const scrollToTop = () => {
+ const c = document.documentElement.scrollTop || document.body.scrollTop;
+ if (c > 0) {
+ window.requestAnimationFrame(scrollToTop);
+ window.scrollTo(0, c - c / 8);
+ }
+};
+// scrollToTop()
+
+
Date
+
getDaysDiffBetweenDates
+
Returns the difference (in days) between two dates.
+
Calculate the difference (in days) between to Date objects.
Converts a date from American format to English format.
+
Use Date.toISOString(), split('T') and replace() to convert a date from American format to English format.
+Throws an error if the passed time cannot be converted to a date.
Loop through an array of functions containing asynchronous events, calling next when each asynchronous event has completed.
+
const chainAsync = fns => { let curr = 0; const next = () => fns[curr++](next); next(); };
+/*
+chainAsync([
+ next => { console.log('0 seconds'); setTimeout(next, 1000); },
+ next => { console.log('1 second'); setTimeout(next, 1000); },
+ next => { console.log('2 seconds'); }
+])
+*/
+
+
compose
+
Performs right-to-left function composition.
+
Use Array.reduce() to perform right-to-left function composition.
+The last (rightmost) function can accept one or more arguments; the remaining functions must be unary.
+
const compose = (...fns) => fns.reduce((f, g) => (...args) => f(g(...args)));
+/*
+const add5 = x => x + 5
+const multiply = (x, y) => x * y
+const multiplyAndAdd5 = compose(add5, multiply)
+multiplyAndAdd5(5, 2) -> 15
+*/
+
+
curry
+
Curries a function.
+
Use recursion.
+If the number of provided arguments (args) is sufficient, call the passed function f.
+Otherwise return a curried function f that expects the rest of the arguments.
+If you want to curry a function that accepts a variable number of arguments (a variadic function, e.g. Math.min()), you can optionally pass the number of arguments to the second parameter arity.
Use console.debug() and the name property of the passed method to log the method's name to the debug channel of the console.
+
const functionName = fn => (console.debug(fn.name), fn);
+// functionName(Math.max) -> max (logged in debug channel of console)
+
+
pipe
+
Performs left-to-right function composition.
+
Use Array.reduce() with the spread operator (...) to perform left-to-right function composition.
+The first (leftmost) function can accept one or more arguments; the remaining functions must be unary.
+
const pipeFunctions = (...fns) => fns.reduce((f, g) => (...args) => g(f(...args)));
+/*
+const add5 = x => x + 5
+const multiply = (x, y) => x * y
+const multiplyAndAdd5 = pipe(multiply, add5)
+multiplyAndAdd5(5, 2) -> 15
+*/
+
+
promisify
+
Converts an asynchronous function to return a promise.
+
Use currying to return a function returning a Promise that calls the original function.
+Use the ...rest operator to pass in all the parameters.
Convert the number to a string, using spread operators in ES6([...string]) build an array.
+Use Array.map() and parseInt() to transform each value to an integer.
Use recursion.
+If n is less than or equal to 1, return 1.
+Otherwise, return the product of n and the factorial of n - 1.
+Throws an exception if n is a negative number.
+
const factorial = n =>
+ n < 0 ? (() => { throw new TypeError('Negative numbers are not allowed!') })()
+ : n <= 1 ? 1 : n * factorial(n - 1);
+// factorial(6) -> 720
+
+
fibonacci
+
Generates an array, containing the Fibonacci sequence, up until the nth term.
+
Create an empty array of the specific length, initializing the first two values (0 and 1).
+Use Array.reduce() to add values into the array, using the sum of the last two values, except for the first two.
Calculates the Hamming distance between two values.
+
Use XOR operator (^) to find the bit difference between the two numbers, convert to binary string using toString(2).
+Count and return the number of 1s in the string, using match(/1/g).
Find the middle of the array, use Array.sort() to sort the values.
+Return the number at the midpoint if length is odd, otherwise the average of the two middle numbers.
Returns true if the given string is a palindrome, false otherwise.
+
Convert string toLowerCase() and use replace() to remove non-alphanumeric characters from it.
+Then, split('') into individual characters, reverse(), join('') and compare to the original, unreversed string, after converting it tolowerCase().
Use Math.round() and template literals to round the number to the specified number of digits.
+Omit the second argument, decimals to round to an integer.
Returns the standard deviation of an array of numbers.
+
Use Array.reduce() to calculate the mean, variance and the sum of the variance of the values, the variance of the values, then
+determine the standard deviation.
+You can omit the second argument to get the sample standard deviation or set it to true to get the population standard deviation.
Use SpeechSynthesisUtterance.voice and window.speechSynthesis.getVoices() to convert a message to speech.
+Use window.speechSynthesis.speak() to play the message.
Returns an array of lines from the specified file.
+
Use readFileSync function in fs node package to create a Buffer from a file.
+convert buffer to string using toString(encoding) function.
+creating an array from contents of file by spliting file content line by line(each \n).
Removes any properties except the ones specified from a JSON object.
+
Use Object.keys() method to loop over given json object and deleting keys that are not included in given array.
+also if you give it a special key(childIndicator) it will search deeply inside it to apply function to inner objects too.
Use Object.assign() and an empty object ({}) to create a shallow clone of the original.
+
const shallowClone = obj => Object.assign({}, obj);
+/*
+const a = { x: true, y: 1 };
+const b = shallowClone(a);
+a === b -> false
+*/
+
+
String
+
anagrams
+
Generates all anagrams of a string (contains duplicates).
+
Use recursion.
+For each letter in the given string, create all the partial anagrams for the rest of its letters.
+Use Array.map() to combine the letter with each partial anagram, then Array.reduce() to combine all anagrams in one array.
+Base cases are for string length equal to 2 or 1.
Use destructuring and toUpperCase() to capitalize first letter, ...rest to get array of characters after first letter and then Array.join('') to make it a string again.
+Omit the lowerRest parameter to keep the rest of the string intact, or set it to true to convert to lower case.
Determine if the string's length is greater than num.
+Return the string truncated to the desired length, with ... appended to the end or the original string.
Extends a 3-digit color code to a 6-digit color code.
+
Use Array.map(), split() and Array.join() to join the mapped array for converting a 3-digit RGB notated hexadecimal color-code to the 6-digit form.
+Array.slice() is used to remove # from string start since it's added once.
Returns lower-cased constructor name of value, "undefined" or "null" if value is undefined or null
+
const getType = v =>
+ v === undefined ? 'undefined' : v === null ? 'null' : v.constructor.name.toLowerCase();
+// getType(new Set([1,2,3])) -> "set"
+
+
hexToRGB
+
Converts a colorcode to a rgb() string.
+
Use bitwise right-shift operator and mask bits with & (and) operator to convert a hexadecimal color code (prefixed with #) to a string with the RGB values. In case it's a 3-digit-colorcode, do the same with the 6-digit-colorcode extended by the extendHex() function (ref. extendHex snippet)
Checks if the given argument is a native boolean element.
+
Use typeof to check if a value is classified as a boolean primitive.
+
const isBoolean = val => typeof val === 'boolean';
+// isBoolean(null) -> false
+// isBoolean(false) -> true
+
+
isFunction
+
Checks if the given argument is a function.
+
Use typeof to check if a value is classified as a function primitive.
+
const isFunction = val => val && typeof val === 'function';
+// isFunction('x') -> false
+// isFunction(x => x) -> true
+
+
isNumber
+
Checks if the given argument is a number.
+
Use typeof to check if a value is classified as a number primitive.
+
const isNumber = val => typeof val === 'number';
+// isNumber('1') -> false
+// isNumber(1) -> true
+
+
isString
+
Checks if the given argument is a string.
+
Use typeof to check if a value is classified as a string primitive.
+
const isString = val => typeof val === 'string';
+// isString(10) -> false
+// isString('10') -> true
+
+
isSymbol
+
Checks if the given argument is a symbol.
+
Use typeof to check if a value is classified as a symbol primitive.
+
const isSymbol = val => typeof val === 'symbol';
+// isSymbol('x') -> false
+// isSymbol(Symbol('x')) -> true
+
+
RGBToHex
+
Converts the values of RGB components to a colorcode.
+
Convert given RGB parameters to hexadecimal string using bitwise left-shift operator (<<) and toString(16), then padStart(6,'0') to get a 6-digit hexadecimal value.
Use the modulo operator (%) to find values of single and tens digits.
+Find which ordinal pattern digits match.
+If digit is found in teens pattern, use teens ordinal.
Returns true if the given value is a number, false otherwise.
+
Use !isNaN in combination with parseFloat() to check if the argument is a number.
+Use isFinite() to check if the number is finite.
+Use Number() to check if the coercion holds.
