Change all snippets from var to const

This commit is contained in:
Jorge Gonzalez
2017-12-12 07:11:37 -05:00
parent 06aa1a7ec9
commit 98279117fa
33 changed files with 35 additions and 35 deletions

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@ -4,6 +4,6 @@ Convert each value to a hexadecimal string, using `toString(16)`, then `padStart
Combine values using `join('')`.
```js
var rgbToHex = (r, g, b) =>
const rgbToHex = (r, g, b) =>
[r,g,b].map( v => v.toString(16).padStart(2,'0')).join('');
```

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@ -5,6 +5,6 @@ Combine all key-value pairs into a single object using `Object.assign()` and the
Pass `location.search` as the argument to apply to the current `url`.
```js
var getUrlParameters = url =>
const getUrlParameters = url =>
Object.assign(...url.match(/([^?=&]+)(=([^&]*))?/g).map(m => {[f,v] = m.split('='); return {[f]:v}}));
```

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@ -3,7 +3,7 @@
Use `crypto` API to generate a UUID, compliant with [RFC4122](https://www.ietf.org/rfc/rfc4122.txt) version 4.
```js
var uuid = _ =>
const uuid = _ =>
( [1e7]+-1e3+-4e3+-8e3+-1e11 ).replace( /[018]/g, c =>
(c ^ crypto.getRandomValues(new Uint8Array(1))[0] & 15 >> c / 4).toString(16)
)

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@ -6,7 +6,7 @@ Use `map()` to combine the letter with each partial anagram, then `reduce()` to
Base cases are for string `length` equal to `2` or `1`.
```js
var anagrams = s => {
const anagrams = s => {
if(s.length <= 2) return s.length === 2 ? [s, s[1] + s[0]] : [s];
return s.split('').reduce( (a,l,i) => {
anagrams(s.slice(0,i) + s.slice(i+1)).map( v => a.push(l+v) );

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@ -3,6 +3,6 @@
Use `reduce()` to add each value to an accumulator, initialized with a value of `0`, divide by the `length` of the array.
```js
var average = arr =>
const average = arr =>
arr.reduce( (acc , val) => acc + val, 0) / arr.length;
```

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@ -3,5 +3,5 @@
Use `slice(0,1)` and `toUpperCase()` to capitalize first letter, `slice(1)` to get the rest of the string.
```js
var capitalize = str => str.slice(0, 1).toUpperCase() + str.slice(1);
const capitalize = str => str.slice(0, 1).toUpperCase() + str.slice(1);
```

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@ -3,5 +3,5 @@
Use `reduce()` to increment a counter each time you encounter the specific value inside the array.
```js
var countOccurrences = (arr, value) => arr.reduce((a, v) => v===value ? a + 1 : a + 0, 0);
const countOccurrences = (arr, value) => arr.reduce((a, v) => v===value ? a + 1 : a + 0, 0);
```

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@ -3,5 +3,5 @@
Use `window.location.href` to get current URL.
```js
var currentUrl = _ => window.location.href;
const currentUrl = _ => window.location.href;
```

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@ -5,7 +5,7 @@ If the number of provided arguments (`args`) is sufficient, call the passed func
Otherwise return a curried function `f` that expects the rest of the arguments.
```js
var curry = f =>
const curry = f =>
(...args) =>
args.length >= f.length ? f(...args) : (...otherArgs) => curry(f)(...args, ...otherArgs)
```

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@ -3,5 +3,5 @@
Use `filter()` to remove values that are part of `values`, determined using `includes()`.
```js
var difference = (arr, values) => arr.filter(v => !values.includes(v));
const difference = (arr, values) => arr.filter(v => !values.includes(v));
```

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@ -3,7 +3,7 @@
Use `replace()` to escape special characters.
```js
var escapeRegExp = s =>
const escapeRegExp = s =>
s.replace(/[.*+?^${}()|[\]\\]/g, '\\$&');
}
```

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@ -4,5 +4,5 @@ Use `Math.abs()` to extend logic to negative numbers, check using the modulo (`%
Return `true` if the number is even, `false` if the number is odd.
```js
var isEven = num => Math.abs(num) % 2 === 0;
const isEven = num => Math.abs(num) % 2 === 0;
```

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@ -4,7 +4,7 @@ Create an empty array of the specific length, initializing the first two values
Use `reduce()` to add values into the array, using the sum of the last two values, except for the first two.
```js
var fibonacci = n =>
const fibonacci = n =>
Array.apply(null, [0,1].concat(Array(n-2))).reduce(
(acc, val, i) => {
acc.push( i>1 ? acc[i-1]+acc[i-2] : val);

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@ -4,6 +4,6 @@ Use recursion.
Use `reduce()` to get all elements that are not arrays, flatten each element that is an array.
```js
var flatten = arr =>
const flatten = arr =>
arr.reduce( (a, v) => a.concat( Array.isArray(v) ? flatten(v) : v ), []);
```

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@ -5,5 +5,5 @@ Base case is when `y` equals `0`. In this case, return `x`.
Otherwise, return the GCD of `y` and the remainder of the division `x/y`.
```js
var gcd = (x , y) => !y ? x : gcd(y, x % y);
const gcd = (x , y) => !y ? x : gcd(y, x % y);
```

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@ -3,5 +3,5 @@
Return `arr[0]`.
```js
var head = arr => arr[0];
const head = arr => arr[0];
```

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@ -3,5 +3,5 @@
Return `arr.slice(0,-1)`.
```js
var initial = arr => arr.slice(0,-1);
const initial = arr => arr.slice(0,-1);
```

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@ -4,6 +4,6 @@ Use `Array(end-start)` to create an array of the desired length, `map()` to fill
You can omit `start` to use a default value of `0`.
```js
var initializeArrayRange = (end, start = 0) =>
const initializeArrayRange = (end, start = 0) =>
Array.apply(null, Array(end-start)).map( (v,i) => i + start );
```

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@ -4,6 +4,6 @@ Use `Array(n)` to create an array of the desired length, `fill(v)` to fill it wi
You can omit `v` to use a default value of `0`.
```js
var initializeArray = (n, v = 0) =>
const initializeArray = (n, v = 0) =>
Array(n).fill(v);
```

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@ -3,5 +3,5 @@
Return `arr.slice(-1)[0]`.
```js
var last = arr => arr.slice(-1)[0];
const last = arr => arr.slice(-1)[0];
```

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@ -4,7 +4,7 @@ Use `performance.now()` to get start and end time for the function, `console.log
First argument is the function name, subsequent arguments are passed to the function.
```js
var timeTaken = (f,...args) => {
const timeTaken = (f,...args) => {
var t0 = performance.now(), r = f(...args);
console.log(performance.now() - t0);
return r;

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@ -3,6 +3,6 @@
Use `map()` to create objects for each key-value pair, combine with `Object.assign()`.
```js
var objectFromPairs = arr =>
const objectFromPairs = arr =>
Object.assign(...arr.map( v => {return {[v[0]] : v[1]};} ));
```

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@ -1,8 +1,8 @@
### Powerset
Use `reduce()` combined with `map()` to iterate over elements and combine into an array containing all combinations.
Use `reduce()` combined with `map()` to iterate over elements and combine into an array containing all combinations.
```js
var powerset = arr =>
const powerset = arr =>
arr.reduce( (a,v) => a.concat(a.map( r => [v].concat(r) )), [[]]);
```

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@ -3,5 +3,5 @@
Use `Math.random()` to generate a random value, map it to the desired range using multiplication.
```js
var randomInRange = (min, max) => Math.random() * (max - min) + min;
const randomInRange = (min, max) => Math.random() * (max - min) + min;
```

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@ -3,5 +3,5 @@
Use `sort()` to reorder elements, utilizing `Math.random()` to randomize the sorting.
```js
var randomizeOrder = arr => arr.sort( (a,b) => Math.random() >= 0.5 ? -1 : 1)
const randomizeOrder = arr => arr.sort( (a,b) => Math.random() >= 0.5 ? -1 : 1)
```

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@ -4,6 +4,6 @@ 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`).
```js
var redirect = (url, asLink = true) =>
const redirect = (url, asLink = true) =>
asLink ? window.location.href = url : window.location.replace(url);
```

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@ -4,5 +4,5 @@ Use array destructuring and `Array.reverse()` to reverse the order of the charac
Combine characters to get a string using `join('')`.
```js
var reverseString = str => [...str].reverse().join('');
const reverseString = str => [...str].reverse().join('');
```

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@ -4,8 +4,8 @@ Get distance from top using `document.documentElement.scrollTop` or `document.bo
Scroll by a fraction of the distance from top. Use `window.requestAnimationFrame()` to animate the scrolling.
```js
var scrollToTop = _ => {
var c = document.documentElement.scrollTop || document.body.scrollTop;
const scrollToTop = _ => {
const c = document.documentElement.scrollTop || document.body.scrollTop;
if(c > 0) {
window.requestAnimationFrame(scrollToTop);
window.scrollTo(0, c - c/8);

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@ -3,5 +3,5 @@
Use `filter()` to remove values that are not part of `values`, determined using `includes()`.
```js
var difference = (arr, values) => arr.filter(v => values.includes(v));
const difference = (arr, values) => arr.filter(v => values.includes(v));
```

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@ -3,6 +3,6 @@
Split the string using `split('')`, `sort()` utilizing `localeCompare()`, recombine using `join('')`.
```js
var sortCharactersInString = str =>
const sortCharactersInString = str =>
str.split('').sort( (a,b) => a.localeCompare(b) ).join('');
```

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@ -3,6 +3,6 @@
Use `reduce()` to add each value to an accumulator, initialized with a value of `0`.
```js
var sum = arr =>
const sum = arr =>
arr.reduce( (acc , val) => acc + val, 0);
```

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@ -3,5 +3,5 @@
Return `arr.slice(1)`.
```js
var tail = arr => arr.slice(1);
const tail = arr => arr.slice(1);
```

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@ -4,5 +4,5 @@ Use `!isNaN` in combination with `parseFloat()` to check if the argument is a nu
Use `isFinite()` to check if the number is finite.
```js
var validateNumber = n => !isNaN(parseFloat(n)) && isFinite(n);
const validateNumber = n => !isNaN(parseFloat(n)) && isFinite(n);
```