Added linting, processed current snippets

README.md

@@ -51,7 +51,7 @@
 * [Random integer in range](#random-integer-in-range)
 * [Random number in range](#random-number-in-range)
 * [Randomize order of array](#randomize-order-of-array)
-* [Redirect to url](#redirect-to-url)
+* [Redirect to URL](#redirect-to-url)
 * [Reverse a string](#reverse-a-string)
 * [RGB to hexadecimal](#rgb-to-hexadecimal)
 * [Run promises in series](#run-promises-in-series)
@@ -78,10 +78,10 @@ Base cases are for string `length` equal to `2` or `1`.
 
 ```js
 const anagrams = str => {
-  if(str.length <= 2)  return str.length === 2 ? [str, str[1] + str[0]] : [str];
+  if (str.length <= 2) return str.length === 2 ? [str, str[1] + str[0]] : [str];
-  return str.split('').reduce( (acc, letter, i) =>
+  return str.split('').reduce((acc, letter, i) =>
-    acc.concat(anagrams(str.slice(0, i) + str.slice(i + 1)).map( val => letter + val )), []);
+    acc.concat(anagrams(str.slice(0, i) + str.slice(i + 1)).map(val => letter + val)), []);
-}
+};
 // anagrams('abc') -> ['abc','acb','bac','bca','cab','cba']
 ```
 
@@ -90,8 +90,7 @@ const anagrams = str => {
 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 =>
+const average = arr => arr.reduce((acc, val) => acc + val, 0) / arr.length;
-  arr.reduce( (acc , val) => acc + val, 0) / arr.length;
 // average([1,2,3]) -> 2
 ```
 
@@ -100,7 +99,7 @@ const average = arr =>
 Use `scrollY`, `scrollHeight` and `clientHeight` to determine if the bottom of the page is visible.
 
 ```js
-const bottomVisible = _ => 
+const bottomVisible = _ =>
   document.documentElement.clientHeight + window.scrollY >= document.documentElement.scrollHeight || document.documentElement.clientHeight;
 // bottomVisible() -> true
 ```
@@ -121,7 +120,7 @@ Omit the `lowerRest` parameter to keep the rest of the string intact, or set it
 
 ```js
 const capitalize = (str, lowerRest = false) =>
-  str.slice(0, 1).toUpperCase() + (lowerRest? str.slice(1).toLowerCase() : str.slice(1));
+  str.slice(0, 1).toUpperCase() + (lowerRest ? str.slice(1).toLowerCase() : str.slice(1));
 // capitalize('myName', true) -> 'Myname'
 ```
 
@@ -130,7 +129,7 @@ const capitalize = (str, lowerRest = false) =>
 Loop through an array of functions containing asynchronous events, calling `next` when each asynchronous event has completed.
 
 ```js
-const chainAsync = fns => { let curr = 0; const next = () => fns[curr++](next); next(); }
+const chainAsync = fns => { let curr = 0; const next = () => fns[curr++](next); next(); };
 /*
 chainAsync([
   next => { console.log('0 seconds'); setTimeout(next, 1000); },
@@ -159,7 +158,7 @@ If the original array can't be split evenly, the final chunk will contain the re
 
 ```js
 const chunk = (arr, size) =>
-  Array.apply(null, {length: Math.ceil(arr.length/size)}).map((v, i) => arr.slice(i*size, i*size+size));
+  Array.apply(null, {length: Math.ceil(arr.length / size)}).map((v, i) => arr.slice(i * size, i * size + size));
 // chunk([1,2,3,4,5], 2) -> [[1,2],[3,4],5]
 ```
 
@@ -207,7 +206,7 @@ Use `Array.reduce()` to get all elements that are not arrays, flatten each eleme
 
 ```js
 const deepFlatten = arr =>
-  arr.reduce( (a, v) => a.concat( Array.isArray(v) ? deepFlatten(v) : v ), []);
+  arr.reduce((a, v) => a.concat(Array.isArray(v) ? deepFlatten(v) : v), []);
 // deepFlatten([1,[2],[[3],4],5]) -> [1,2,3,4,5]
 ```
 
@@ -274,8 +273,8 @@ Create an empty array of the specific length, initializing the first two values
 Use `Array.reduce()` to add values into the array, using the sum of the last two values, except for the first two.
 
 ```js
-const fibonacci = n => 
+const fibonacci = n =>
-  Array(n).fill(0).reduce((acc, val, i) => acc.concat(i > 1 ? acc[i - 1] + acc[i - 2] : i),[]);
+  Array(n).fill(0).reduce((acc, val, i) => acc.concat(i > 1 ? acc[i - 1] + acc[i - 2] : i), []);
 // fibonacci(5) -> [0,1,1,2,3]
 ```
 
@@ -293,7 +292,7 @@ const filterNonUnique = arr => arr.filter(i => arr.indexOf(i) === arr.lastIndexO
 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), []);
+const flatten = arr => arr.reduce((a, v) => a.concat(v), []);
 // flatten([1,[2],3,4]) -> [1,2,3,4]
 ```
 
@@ -321,7 +320,7 @@ Returns lower-cased constructor name of value, "undefined" or "null" if value is
 
 ```js
 const getType = v =>
-  v === undefined ? "undefined" : v === null ? "null" : v.constructor.name.toLowerCase(); 
+  v === undefined ? 'undefined' : v === null ? 'null' : v.constructor.name.toLowerCase();
 // getType(new Set([1,2,3])) -> "set"
 ```
 
@@ -332,8 +331,8 @@ You can omit `el` to use a default value of `window`.
 
 ```js
 const getScrollPos = (el = window) =>
-  ( {x: (el.pageXOffset !== undefined) ? el.pageXOffset : el.scrollLeft,
+  ({x: (el.pageXOffset !== undefined) ? el.pageXOffset : el.scrollLeft,
-   y: (el.pageYOffset !== undefined) ? el.pageYOffset : el.scrollTop} );
+    y: (el.pageYOffset !== undefined) ? el.pageYOffset : el.scrollTop});
 // getScrollPos() -> {x: 0, y: 200}
 ```
 
@@ -344,7 +343,7 @@ 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
-const gcd = (x , y) => !y ? x : gcd(y, x % y);
+const gcd = (x, y) => !y ? x : gcd(y, x % y);
 // gcd (8, 36) -> 4
 ```
 
@@ -355,7 +354,7 @@ Count and return the number of `1`s in the string, using `match(/1/g)`.
 
 ```js
 const hammingDistance = (num1, num2) =>
-  ((num1^num2).toString(2).match(/1/g) || '').length;
+  ((num1 ^ num2).toString(2).match(/1/g) || '').length;
 // hammingDistance(2,3) -> 1
 ```
 
@@ -373,7 +372,7 @@ const head = arr => arr[0];
 Return `arr.slice(0,-1)`.
 
 ```js
-const initial = arr => arr.slice(0,-1);
+const initial = arr => arr.slice(0, -1);
 // initial([1,2,3]) -> [1,2]
 ```
 
@@ -384,7 +383,7 @@ You can omit `start` to use a default value of `0`.
 
 ```js
 const initializeArrayRange = (end, start = 0) =>
-  Array.apply(null, Array(end-start)).map( (v,i) => i + start );
+  Array.apply(null, Array(end - start)).map((v, i) => i + start);
 // initializeArrayRange(5) -> [0,1,2,3,4]
 ```
 
@@ -417,7 +416,7 @@ const timeTaken = callback => {
   const t0 = performance.now(), r = callback();
   console.log(performance.now() - t0);
   return r;
-}
+};
 // timeTaken(() => Math.pow(2, 10)) -> 1024 (0.010000000009313226 logged in console)
 ```
 
@@ -428,9 +427,9 @@ Return the number at the midpoint if `length` is odd, otherwise the average of t
 
 ```js
 const median = arr => {
-  const mid = Math.floor(arr.length / 2), nums = arr.sort((a,b) => a - b);
+  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
 ```
@@ -440,7 +439,7 @@ const median = arr => {
 Use `Array.reduce()` to create and combine key-value pairs.
 
 ```js
-const objectFromPairs = arr => arr.reduce((a,v) => (a[v[0]] = v[1], a), {});
+const objectFromPairs = arr => arr.reduce((a, v) => (a[v[0]] = v[1], a), {});
 // objectFromPairs([['a',1],['b',2]]) -> {a: 1, b: 2}
 ```
 
@@ -470,7 +469,7 @@ Use `Array.reduce()` combined with `Array.map()` to iterate over elements and co
 
 ```js
 const powerset = arr =>
-  arr.reduce( (a,v) => a.concat(a.map( r => [v].concat(r) )), [[]]);
+  arr.reduce((a, v) => a.concat(a.map(r => [v].concat(r))), [[]]);
 // powerset([1,2]) -> [[], [1], [2], [2,1]]
 ```
 
@@ -515,7 +514,7 @@ const randomInRange = (min, max) => Math.random() * (max - min) + min;
 Use `Array.sort()` to reorder elements, utilizing `Math.random()` to randomize the sorting.
 
 ```js
-const 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);
 // randomizeOrder([1,2,3]) -> [1,3,2]
 ```
 
@@ -567,11 +566,11 @@ Scroll by a fraction of the distance from top. Use `window.requestAnimationFrame
 ```js
 const scrollToTop = _ => {
   const c = document.documentElement.scrollTop || document.body.scrollTop;
-  if(c > 0) {
+  if (c > 0) {
     window.requestAnimationFrame(scrollToTop);
-    window.scrollTo(0, c - c/8);
+    window.scrollTo(0, c - c / 8);
   }
-}
+};
 // scrollToTop()
 ```
 
@@ -583,8 +582,8 @@ Use `Array.sort()` to sort the elements of the original array based on the rando
 ```js
 const shuffle = arr => {
   let r = arr.map(Math.random);
-  return arr.sort((a,b) => r[a] - r[b]);
+  return arr.sort((a, b) => r[a] - r[b]);
-}
+};
 // shuffle([1,2,3]) -> [2, 1, 3]
 ```
 
@@ -603,7 +602,7 @@ Split the string using `split('')`, `Array.sort()` utilizing `localeCompare()`,
 
 ```js
 const sortCharactersInString = str =>
-  str.split('').sort( (a,b) => a.localeCompare(b) ).join('');
+  str.split('').sort((a, b) => a.localeCompare(b)).join('');
 // sortCharactersInString('cabbage') -> 'aabbceg'
 ```
 
@@ -612,7 +611,7 @@ const sortCharactersInString = str =>
 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);
+const sum = arr => arr.reduce((acc, val) => acc + val, 0);
 // sum([1,2,3,4]) -> 10
 ```
 
@@ -642,7 +641,7 @@ Return the string truncated to the desired length, with `...` appended to the en
 
 ```js
 const truncate = (str, num) =>
-  str.length > num ? str.slice(0, num > 3 ? num-3 : num) + '...' : str;
+  str.length > num ? str.slice(0, num > 3 ? num - 3 : num) + '...' : str;
 // truncate('boomerang', 7) -> 'boom...'
 ```
 
@@ -663,7 +662,7 @@ 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), {}
+    (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'}
 ```
@@ -674,7 +673,7 @@ Use `crypto` API to generate a UUID, compliant with [RFC4122](https://www.ietf.o
 
 ```js
 const uuid = _ =>
-  ( [1e7]+-1e3+-4e3+-8e3+-1e11 ).replace( /[018]/g, c =>
+  ([1e7] + -1e3 + -4e3 + -8e3 + -1e11).replace(/[018]/g, c =>
     (c ^ crypto.getRandomValues(new Uint8Array(1))[0] & 15 >> c / 4).toString(16)
   );
 // uuid() -> '7982fcfe-5721-4632-bede-6000885be57d'

currentSnippet.js

@@ -0,0 +1,3 @@
+
+const valueOrDefault = (value, d) => value || d;
+// valueOrDefault(NaN, 30) -> 30

package.json

@@ -4,7 +4,8 @@
     "fs-extra": "^4.0.2",
     "live-server": "^1.2.0",
     "markdown-it": "^8.4.0",
-    "nodemon": "^1.12.1"
+    "nodemon": "^1.12.1",
+    "semistandard": "^11.0.0"
   },
   "name": "30-seconds-of-code",
   "description": "A collection of useful Javascript snippets.",
@@ -13,6 +14,7 @@
   "devDependencies": {},
   "scripts": {
     "build-list": "node ./scripts/builder.js",
+    "lint": "node ./scripts/lintSnippet.js",
     "start": "concurrently --kill-others \"nodemon -e js,md -i README.md -x \\\"npm run build-list\\\"\" \"live-server ./build\""
   },
   "repository": {

scripts/builder.js

@@ -6,6 +6,8 @@ var staticPartsPath = './static-parts';
 
 var snippets = {}, startPart = '', endPart = '', output = '';
 
+console.time('Builder');
+
 try {
   var snippetFilenames = fs.readdirSync(snippetsPath);
   snippetFilenames.sort((a, b) => {
@@ -51,3 +53,5 @@ catch (err){
   console.log('Error during README generation: '+err);
   process.exit(1);
 }
+
+console.timeEnd('Builder');

scripts/lintSnippet.js

@@ -0,0 +1,31 @@
+var fs = require('fs-extra');
+var cp = require('child_process');
+var path = require('path');
+
+var snippetsPath = './snippets';
+var snippetFilename = '';
+
+console.time('Linter');
+
+if(process.argv.length < 3){
+  console.log('Please specify the filename of a snippet to be linted.');
+  console.log('Example usage: npm run lint "snippet-file.md"');
+  process.exit(0);
+}
+else {
+  snippetFilename = process.argv[2];
+  let snippetData = fs.readFileSync(path.join(snippetsPath,snippetFilename),'utf8');
+  try {
+    let originalCode = snippetData.slice(snippetData.indexOf('```js')+5,snippetData.lastIndexOf('```'));
+    fs.writeFileSync('currentSnippet.js',`${originalCode}`);
+    cp.exec('semistandard "currentSnippet.js" --fix',{},(error, stdOut, stdErr) => {
+      let lintedCode = fs.readFileSync('currentSnippet.js','utf8');
+      fs.writeFile(path.join(snippetsPath,snippetFilename), `${snippetData.slice(0, snippetData.indexOf('```js')+5)+lintedCode+'```\n'}`);
+      console.timeEnd('Linter');
+    });
+  }
+  catch (err){
+    console.log('Error during snippet loading: '+err);
+    process.exit(1);
+  }
+}

semi-snippets.js

@@ -0,0 +1,242 @@
+
+const anagrams = str => {
+  if (str.length <= 2) return str.length === 2 ? [str, str[1] + str[0]] : [str];
+  return str.split('').reduce((acc, letter, i) =>
+    acc.concat(anagrams(str.slice(0, i) + str.slice(i + 1)).map(val => letter + val)), []);
+};
+// anagrams('abc') -> ['abc','acb','bac','bca','cab','cba']
+
+const average = arr =>
+  arr.reduce((acc, val) => acc + val, 0) / arr.length;
+// average([1,2,3]) -> 2
+
+const bottomVisible = _ =>
+  document.documentElement.clientHeight + window.scrollY >= document.documentElement.scrollHeight || document.documentElement.clientHeight;
+// bottomVisible() -> true
+
+const capitalizeEveryWord = str => str.replace(/\b[a-z]/g, char => char.toUpperCase());
+// capitalizeEveryWord('hello world!') -> 'Hello World!'
+
+const capitalize = (str, lowerRest = false) =>
+  str.slice(0, 1).toUpperCase() + (lowerRest ? str.slice(1).toLowerCase() : str.slice(1));
+// capitalize('myName', true) -> 'Myname'
+
+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'); }
+])
+*/
+
+const palindrome = str =>
+  str.toLowerCase().replace(/[\W_]/g, '').split('').reverse().join('') === str.toLowerCase().replace(/[\W_]/g, '');
+// palindrome('taco cat') -> true
+
+const chunk = (arr, size) =>
+  Array.apply(null, {length: Math.ceil(arr.length / size)}).map((v, i) => arr.slice(i * size, i * size + size));
+// chunk([1,2,3,4,5], 2) -> [[1,2],[3,4],5]
+
+const countOccurrences = (arr, value) => arr.reduce((a, v) => v === value ? a + 1 : a + 0, 0);
+// countOccurrences([1,1,2,1,2,3], 1) -> 3
+
+const currentUrl = _ => window.location.href;
+// currentUrl() -> 'https://google.com'
+
+const curry = (f, arity = f.length, next) =>
+  (next = prevArgs =>
+    nextArg => {
+      const args = [ ...prevArgs, nextArg ];
+      return args.length >= arity ? f(...args) : next(args);
+    }
+  )([]);
+// curry(Math.pow)(2)(10) -> 1024
+// curry(Math.min, 3)(10)(50)(2) -> 2
+
+const deepFlatten = arr =>
+  arr.reduce((a, v) => a.concat(Array.isArray(v) ? deepFlatten(v) : v), []);
+// deepFlatten([1,[2],[[3],4],5]) -> [1,2,3,4,5]
+
+const difference = (arr, values) => arr.filter(v => !values.includes(v));
+// difference([1,2,3], [1,2]) -> [3]
+
+const distance = (x0, y0, x1, y1) => Math.hypot(x1 - x0, y1 - y0);
+// distance(1,1, 2,3) -> 2.23606797749979
+
+const isDivisible = (dividend, divisor) => dividend % divisor === 0;
+// isDivisible(6,3) -> true
+
+const escapeRegExp = str => str.replace(/[.*+?^${}()|[\]\\]/g, '\\$&');
+// escapeRegExp('(test)') -> \\(test\\)
+
+const isEven = num => Math.abs(num) % 2 === 0;
+// isEven(3) -> false
+
+const factorial = n => n <= 1 ? 1 : n * factorial(n - 1);
+// factorial(6) -> 720
+
+const fibonacci = n =>
+  Array(n).fill(0).reduce((acc, val, i) => acc.concat(i > 1 ? acc[i - 1] + acc[i - 2] : i), []);
+// fibonacci(5) -> [0,1,1,2,3]
+
+const filterNonUnique = arr => arr.filter(i => arr.indexOf(i) === arr.lastIndexOf(i));
+// filterNonUnique([1,2,2,3,4,4,5]) -> [1,3,5]
+
+const flatten = arr => arr.reduce((a, v) => a.concat(v), []);
+// flatten([1,[2],3,4]) -> [1,2,3,4]
+
+const arrayMax = arr => Math.max(...arr);
+// arrayMax([10, 1, 5]) -> 10
+
+const arrayMin = arr => Math.min(...arr);
+// arrayMin([10, 1, 5]) -> 1
+
+const getType = v =>
+  v === undefined ? 'undefined' : v === null ? 'null' : v.constructor.name.toLowerCase();
+// getType(new Set([1,2,3])) -> "set"
+
+const getScrollPos = (el = window) =>
+  ({x: (el.pageXOffset !== undefined) ? el.pageXOffset : el.scrollLeft,
+    y: (el.pageYOffset !== undefined) ? el.pageYOffset : el.scrollTop});
+// getScrollPos() -> {x: 0, y: 200}
+
+const gcd = (x, y) => !y ? x : gcd(y, x % y);
+// gcd (8, 36) -> 4
+
+const hammingDistance = (num1, num2) =>
+  ((num1 ^ num2).toString(2).match(/1/g) || '').length;
+// hammingDistance(2,3) -> 1
+
+const head = arr => arr[0];
+// head([1,2,3]) -> 1
+
+const initial = arr => arr.slice(0, -1);
+// initial([1,2,3]) -> [1,2]
+
+const initializeArrayRange = (end, start = 0) =>
+  Array.apply(null, Array(end - start)).map((v, i) => i + start);
+// initializeArrayRange(5) -> [0,1,2,3,4]
+
+const initializeArray = (n, value = 0) => Array(n).fill(value);
+// initializeArray(5, 2) -> [2,2,2,2,2]
+
+const last = arr => arr.slice(-1)[0];
+// last([1,2,3]) -> 3
+
+const timeTaken = callback => {
+  const t0 = performance.now(), r = callback();
+  console.log(performance.now() - t0);
+  return r;
+};
+// timeTaken(() => Math.pow(2, 10)) -> 1024 (0.010000000009313226 logged in console)
+
+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
+
+const objectFromPairs = arr => arr.reduce((a, v) => (a[v[0]] = v[1], a), {});
+// objectFromPairs([['a',1],['b',2]]) -> {a: 1, b: 2}
+
+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
+
+const pipe = (...funcs) => arg => funcs.reduce((acc, func) => func(acc), arg);
+// pipe(btoa, x => x.toUpperCase())("Test") -> "VGVZDA=="
+
+const powerset = arr =>
+  arr.reduce((a, v) => a.concat(a.map(r => [v].concat(r))), [[]]);
+// powerset([1,2]) -> [[], [1], [2], [2,1]]
+
+const promisify = func =>
+  (...args) =>
+    new Promise((resolve, reject) =>
+      func(...args, (err, result) =>
+        err ? reject(err) : resolve(result))
+    );
+// const delay = promisify((d, cb) => setTimeout(cb, d))
+// delay(2000).then(() => console.log('Hi!')) -> Promise resolves after 2s
+
+const randomIntegerInRange = (min, max) => Math.floor(Math.random() * (max - min + 1)) + min;
+// randomIntegerInRange(0, 5) -> 2
+
+const randomInRange = (min, max) => Math.random() * (max - min) + min;
+// randomInRange(2,10) -> 6.0211363285087005
+
+const randomizeOrder = arr => arr.sort((a, b) => Math.random() >= 0.5 ? -1 : 1);
+// randomizeOrder([1,2,3]) -> [1,3,2]
+
+const redirect = (url, asLink = true) =>
+  asLink ? window.location.href = url : window.location.replace(url);
+// redirect('https://google.com')
+
+const reverseString = str => [...str].reverse().join('');
+// reverseString('foobar') -> 'raboof'
+
+const rgbToHex = (r, g, b) => ((r << 16) + (g << 8) + b).toString(16).padStart(6, '0');
+// rgbToHex(255, 165, 1) -> 'ffa501'
+
+const series = 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
+
+const scrollToTop = _ => {
+  const c = document.documentElement.scrollTop || document.body.scrollTop;
+  if (c > 0) {
+    window.requestAnimationFrame(scrollToTop);
+    window.scrollTo(0, c - c / 8);
+  }
+};
+// scrollToTop()
+
+const shuffle = arr => {
+  let r = arr.map(Math.random);
+  return arr.sort((a, b) => r[a] - r[b]);
+};
+// shuffle([1,2,3]) -> [2, 1, 3]
+
+const similarity = (arr, values) => arr.filter(v => values.includes(v));
+// similarity([1,2,3], [1,2,4]) -> [1,2]
+
+const sortCharactersInString = str =>
+  str.split('').sort((a, b) => a.localeCompare(b)).join('');
+// sortCharactersInString('cabbage') -> 'aabbceg'
+
+const sum = arr => arr.reduce((acc, val) => acc + val, 0);
+// sum([1,2,3,4]) -> 10
+
+[varA, varB] = [varB, varA];
+// [x, y] = [y, x]
+
+const tail = arr => arr.length > 1 ? arr.slice(1) : arr;
+// tail([1,2,3]) -> [2,3]
+// tail([1]) -> [1]
+
+const truncate = (str, num) =>
+  str.length > num ? str.slice(0, num > 3 ? num - 3 : num) + '...' : str;
+// truncate('boomerang', 7) -> 'boom...'
+
+const unique = arr => [...new Set(arr)];
+// unique([1,2,2,3,4,4,5]) -> [1,2,3,4,5]
+
+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'}
+
+const uuid = _ =>
+  ([1e7] + -1e3 + -4e3 + -8e3 + -1e11).replace(/[018]/g, c =>
+    (c ^ crypto.getRandomValues(new Uint8Array(1))[0] & 15 >> c / 4).toString(16)
+  );
+// uuid() -> '7982fcfe-5721-4632-bede-6000885be57d'
+
+const validateNumber = n => !isNaN(parseFloat(n)) && isFinite(n);
+// validateNumber('10') -> true
+
+const valueOrDefault = (value, d) => value || d;
+// valueOrDefault(NaN, 30) -> 30

snippets.js

@@ -0,0 +1,302 @@
+
+const anagrams = str => {
+  if(str.length <= 2)  return str.length === 2 ? [str, str[1] + str[0]] : [str];
+  return str.split('').reduce( (acc, letter, i) =>
+    acc.concat(anagrams(str.slice(0, i) + str.slice(i + 1)).map( val => letter + val )), []);
+}
+// anagrams('abc') -> ['abc','acb','bac','bca','cab','cba']
+
+
+const average = arr =>
+  arr.reduce( (acc , val) => acc + val, 0) / arr.length;
+// average([1,2,3]) -> 2
+
+
+const bottomVisible = _ => 
+  document.documentElement.clientHeight + window.scrollY >= document.documentElement.scrollHeight || document.documentElement.clientHeight;
+// bottomVisible() -> true
+
+
+const capitalizeEveryWord = str => str.replace(/\b[a-z]/g, char => char.toUpperCase());
+// capitalizeEveryWord('hello world!') -> 'Hello World!'
+
+
+const capitalize = (str, lowerRest = false) =>
+  str.slice(0, 1).toUpperCase() + (lowerRest? str.slice(1).toLowerCase() : str.slice(1));
+// capitalize('myName', true) -> 'Myname'
+
+
+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'); }
+])
+*/
+
+
+const palindrome = str =>
+  str.toLowerCase().replace(/[\W_]/g,'').split('').reverse().join('') === str.toLowerCase().replace(/[\W_]/g,'');
+// palindrome('taco cat') -> true
+ 
+
+const chunk = (arr, size) =>
+  Array.apply(null, {length: Math.ceil(arr.length/size)}).map((v, i) => arr.slice(i*size, i*size+size));
+// chunk([1,2,3,4,5], 2) -> [[1,2],[3,4],5]
+
+
+const countOccurrences = (arr, value) => arr.reduce((a, v) => v === value ? a + 1 : a + 0, 0);
+// countOccurrences([1,1,2,1,2,3], 1) -> 3
+
+
+const currentUrl = _ => window.location.href;
+// currentUrl() -> 'https://google.com'
+
+
+const curry = (f, arity = f.length, next) =>
+  (next = prevArgs =>
+    nextArg => {
+      const args = [ ...prevArgs, nextArg ];
+      return args.length >= arity ? f(...args) : next(args);
+    }
+  )([]);
+// curry(Math.pow)(2)(10) -> 1024
+// curry(Math.min, 3)(10)(50)(2) -> 2
+
+
+const deepFlatten = arr =>
+  arr.reduce( (a, v) => a.concat( Array.isArray(v) ? deepFlatten(v) : v ), []);
+// deepFlatten([1,[2],[[3],4],5]) -> [1,2,3,4,5]
+
+
+const difference = (arr, values) => arr.filter(v => !values.includes(v));
+// difference([1,2,3], [1,2]) -> [3]
+
+
+const distance = (x0, y0, x1, y1) => Math.hypot(x1 - x0, y1 - y0);
+// distance(1,1, 2,3) -> 2.23606797749979
+
+
+const isDivisible = (dividend, divisor) => dividend % divisor === 0;
+// isDivisible(6,3) -> true
+
+
+const escapeRegExp = str => str.replace(/[.*+?^${}()|[\]\\]/g, '\\$&');
+// escapeRegExp('(test)') -> \\(test\\)
+
+
+const isEven = num => Math.abs(num) % 2 === 0;
+// isEven(3) -> false
+
+
+const factorial = n => n <= 1 ? 1 : n * factorial(n - 1);
+// factorial(6) -> 720
+
+
+const fibonacci = n => 
+  Array(n).fill(0).reduce((acc, val, i) => acc.concat(i > 1 ? acc[i - 1] + acc[i - 2] : i),[]);
+// fibonacci(5) -> [0,1,1,2,3]
+
+
+const filterNonUnique = arr => arr.filter(i => arr.indexOf(i) === arr.lastIndexOf(i));
+// filterNonUnique([1,2,2,3,4,4,5]) -> [1,3,5]
+
+
+const flatten = arr => arr.reduce( (a, v) => a.concat(v), []);
+// flatten([1,[2],3,4]) -> [1,2,3,4]
+
+
+const arrayMax = arr => Math.max(...arr);
+// arrayMax([10, 1, 5]) -> 10
+
+
+const arrayMin = arr => Math.min(...arr);
+// arrayMin([10, 1, 5]) -> 1
+
+
+const getType = v =>
+  v === undefined ? "undefined" : v === null ? "null" : v.constructor.name.toLowerCase(); 
+// getType(new Set([1,2,3])) -> "set"
+
+
+const getScrollPos = (el = window) =>
+  ( {x: (el.pageXOffset !== undefined) ? el.pageXOffset : el.scrollLeft,
+   y: (el.pageYOffset !== undefined) ? el.pageYOffset : el.scrollTop} );
+// getScrollPos() -> {x: 0, y: 200}
+
+
+const gcd = (x , y) => !y ? x : gcd(y, x % y);
+// gcd (8, 36) -> 4
+
+
+const hammingDistance = (num1, num2) =>
+  ((num1^num2).toString(2).match(/1/g) || '').length;
+// hammingDistance(2,3) -> 1
+
+
+const head = arr => arr[0];
+// head([1,2,3]) -> 1
+
+
+const initial = arr => arr.slice(0,-1);
+// initial([1,2,3]) -> [1,2]
+
+
+const initializeArrayRange = (end, start = 0) =>
+  Array.apply(null, Array(end-start)).map( (v,i) => i + start );
+// initializeArrayRange(5) -> [0,1,2,3,4]
+
+
+const initializeArray = (n, value = 0) => Array(n).fill(value);
+// initializeArray(5, 2) -> [2,2,2,2,2]
+
+
+const last = arr => arr.slice(-1)[0];
+// last([1,2,3]) -> 3
+
+
+const timeTaken = callback => {
+  const t0 = performance.now(), r = callback();
+  console.log(performance.now() - t0);
+  return r;
+}
+// timeTaken(() => Math.pow(2, 10)) -> 1024 (0.010000000009313226 logged in console)
+
+
+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
+
+
+const objectFromPairs = arr => arr.reduce((a,v) => (a[v[0]] = v[1], a), {});
+// objectFromPairs([['a',1],['b',2]]) -> {a: 1, b: 2}
+
+
+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
+ 
+
+const pipe = (...funcs) => arg => funcs.reduce((acc, func) => func(acc), arg);
+// pipe(btoa, x => x.toUpperCase())("Test") -> "VGVZDA=="
+
+
+const powerset = arr =>
+  arr.reduce( (a,v) => a.concat(a.map( r => [v].concat(r) )), [[]]);
+// powerset([1,2]) -> [[], [1], [2], [2,1]]
+
+
+const promisify = func =>
+  (...args) =>
+    new Promise((resolve, reject) =>
+      func(...args, (err, result) =>
+        err ? reject(err) : resolve(result))
+    );
+// const delay = promisify((d, cb) => setTimeout(cb, d))
+// delay(2000).then(() => console.log('Hi!')) -> Promise resolves after 2s
+
+
+const randomIntegerInRange = (min, max) => Math.floor(Math.random() * (max - min + 1)) + min;
+// randomIntegerInRange(0, 5) -> 2
+
+
+const randomInRange = (min, max) => Math.random() * (max - min) + min;
+// randomInRange(2,10) -> 6.0211363285087005
+
+
+const randomizeOrder = arr => arr.sort( (a,b) => Math.random() >= 0.5 ? -1 : 1);
+// randomizeOrder([1,2,3]) -> [1,3,2]
+
+
+const redirect = (url, asLink = true) =>
+  asLink ? window.location.href = url : window.location.replace(url);
+// redirect('https://google.com')
+
+
+const reverseString = str => [...str].reverse().join('');
+// reverseString('foobar') -> 'raboof'
+
+
+const rgbToHex = (r, g, b) => ((r << 16) + (g << 8) + b).toString(16).padStart(6, '0');
+// rgbToHex(255, 165, 1) -> 'ffa501'
+
+
+const series = 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
+
+
+const scrollToTop = _ => {
+  const c = document.documentElement.scrollTop || document.body.scrollTop;
+  if(c > 0) {
+    window.requestAnimationFrame(scrollToTop);
+    window.scrollTo(0, c - c/8);
+  }
+}
+// scrollToTop()
+
+
+const shuffle = arr => {
+  let r = arr.map(Math.random);
+  return arr.sort((a,b) => r[a] - r[b]);
+}
+// shuffle([1,2,3]) -> [2, 1, 3]
+
+
+const similarity = (arr, values) => arr.filter(v => values.includes(v));
+// similarity([1,2,3], [1,2,4]) -> [1,2]
+
+
+const sortCharactersInString = str =>
+  str.split('').sort( (a,b) => a.localeCompare(b) ).join('');
+// sortCharactersInString('cabbage') -> 'aabbceg'
+
+
+const sum = arr => arr.reduce( (acc , val) => acc + val, 0);
+// sum([1,2,3,4]) -> 10
+
+
+[varA, varB] = [varB, varA];
+// [x, y] = [y, x]
+
+
+const tail = arr => arr.length > 1 ? arr.slice(1) : arr;
+// tail([1,2,3]) -> [2,3]
+// tail([1]) -> [1]
+
+
+const truncate = (str, num) =>
+  str.length > num ? str.slice(0, num > 3 ? num-3 : num) + '...' : str;
+// truncate('boomerang', 7) -> 'boom...'
+
+
+const unique = arr => [...new Set(arr)];
+// unique([1,2,2,3,4,4,5]) -> [1,2,3,4,5]
+
+
+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'}
+
+
+const uuid = _ =>
+  ( [1e7]+-1e3+-4e3+-8e3+-1e11 ).replace( /[018]/g, c =>
+    (c ^ crypto.getRandomValues(new Uint8Array(1))[0] & 15 >> c / 4).toString(16)
+  );
+// uuid() -> '7982fcfe-5721-4632-bede-6000885be57d'
+
+
+const validateNumber = n => !isNaN(parseFloat(n)) && isFinite(n);
+// validateNumber('10') -> true
+
+
+const valueOrDefault = (value, d) => value || d;
+// valueOrDefault(NaN, 30) -> 30
+
+

snippets/URL-parameters.md

@@ -6,7 +6,7 @@ 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), {}
+    (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'}
 ```

snippets/UUID-generator.md

@@ -4,7 +4,7 @@ Use `crypto` API to generate a UUID, compliant with [RFC4122](https://www.ietf.o
 
 ```js
 const uuid = _ =>
-  ( [1e7]+-1e3+-4e3+-8e3+-1e11 ).replace( /[018]/g, c =>
+  ([1e7] + -1e3 + -4e3 + -8e3 + -1e11).replace(/[018]/g, c =>
     (c ^ crypto.getRandomValues(new Uint8Array(1))[0] & 15 >> c / 4).toString(16)
   );
 // uuid() -> '7982fcfe-5721-4632-bede-6000885be57d'

snippets/anagrams-of-string-(with-duplicates).md

@@ -7,9 +7,9 @@ Base cases are for string `length` equal to `2` or `1`.
 
 ```js
 const anagrams = str => {
-  if(str.length <= 2)  return str.length === 2 ? [str, str[1] + str[0]] : [str];
+  if (str.length <= 2) return str.length === 2 ? [str, str[1] + str[0]] : [str];
-  return str.split('').reduce( (acc, letter, i) =>
+  return str.split('').reduce((acc, letter, i) =>
-    acc.concat(anagrams(str.slice(0, i) + str.slice(i + 1)).map( val => letter + val )), []);
+    acc.concat(anagrams(str.slice(0, i) + str.slice(i + 1)).map(val => letter + val)), []);
-}
+};
 // anagrams('abc') -> ['abc','acb','bac','bca','cab','cba']
 ```

snippets/average-of-array-of-numbers.md

@@ -3,7 +3,6 @@
 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 =>
+const average = arr => arr.reduce((acc, val) => acc + val, 0) / arr.length;
-  arr.reduce( (acc , val) => acc + val, 0) / arr.length;
 // average([1,2,3]) -> 2
 ```

snippets/bottom-visible.md

@@ -3,7 +3,7 @@
 Use `scrollY`, `scrollHeight` and `clientHeight` to determine if the bottom of the page is visible.
 
 ```js
-const bottomVisible = _ => 
+const bottomVisible = _ =>
   document.documentElement.clientHeight + window.scrollY >= document.documentElement.scrollHeight || document.documentElement.clientHeight;
 // bottomVisible() -> true
 ```

snippets/capitalize-first-letter.md

@@ -5,6 +5,6 @@ Omit the `lowerRest` parameter to keep the rest of the string intact, or set it
 
 ```js
 const capitalize = (str, lowerRest = false) =>
-  str.slice(0, 1).toUpperCase() + (lowerRest? str.slice(1).toLowerCase() : str.slice(1));
+  str.slice(0, 1).toUpperCase() + (lowerRest ? str.slice(1).toLowerCase() : str.slice(1));
 // capitalize('myName', true) -> 'Myname'
 ```

snippets/chain-asynchronous-functions.md

@@ -3,7 +3,7 @@
 Loop through an array of functions containing asynchronous events, calling `next` when each asynchronous event has completed.
 
 ```js
-const chainAsync = fns => { let curr = 0; const next = () => fns[curr++](next); next(); }
+const chainAsync = fns => { let curr = 0; const next = () => fns[curr++](next); next(); };
 /*
 chainAsync([
   next => { console.log('0 seconds'); setTimeout(next, 1000); },

snippets/chunk-array.md

@@ -6,6 +6,6 @@ If the original array can't be split evenly, the final chunk will contain the re
 
 ```js
 const chunk = (arr, size) =>
-  Array.apply(null, {length: Math.ceil(arr.length/size)}).map((v, i) => arr.slice(i*size, i*size+size));
+  Array.apply(null, {length: Math.ceil(arr.length / size)}).map((v, i) => arr.slice(i * size, i * size + size));
 // chunk([1,2,3,4,5], 2) -> [[1,2],[3,4],5]
 ```

snippets/deep-flatten-array.md

@@ -5,6 +5,6 @@ Use `Array.reduce()` to get all elements that are not arrays, flatten each eleme
 
 ```js
 const deepFlatten = arr =>
-  arr.reduce( (a, v) => a.concat( Array.isArray(v) ? deepFlatten(v) : v ), []);
+  arr.reduce((a, v) => a.concat(Array.isArray(v) ? deepFlatten(v) : v), []);
 // deepFlatten([1,[2],[[3],4],5]) -> [1,2,3,4,5]
 ```

snippets/fibonacci-array-generator.md

@@ -4,7 +4,7 @@ Create an empty array of the specific length, initializing the first two values
 Use `Array.reduce()` to add values into the array, using the sum of the last two values, except for the first two.
 
 ```js
-const fibonacci = n => 
+const fibonacci = n =>
-  Array(n).fill(0).reduce((acc, val, i) => acc.concat(i > 1 ? acc[i - 1] + acc[i - 2] : i),[]);
+  Array(n).fill(0).reduce((acc, val, i) => acc.concat(i > 1 ? acc[i - 1] + acc[i - 2] : i), []);
 // fibonacci(5) -> [0,1,1,2,3]
 ```

snippets/flatten-array.md

@@ -3,6 +3,6 @@
 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), []);
+const flatten = arr => arr.reduce((a, v) => a.concat(v), []);
 // flatten([1,[2],3,4]) -> [1,2,3,4]
 ```

snippets/get-native-type-of-value.md

@@ -4,6 +4,6 @@ Returns lower-cased constructor name of value, "undefined" or "null" if value is
 
 ```js
 const getType = v =>
-  v === undefined ? "undefined" : v === null ? "null" : v.constructor.name.toLowerCase(); 
+  v === undefined ? 'undefined' : v === null ? 'null' : v.constructor.name.toLowerCase();
 // getType(new Set([1,2,3])) -> "set"
 ```

snippets/get-scroll-position.md

@@ -5,7 +5,7 @@ You can omit `el` to use a default value of `window`.
 
 ```js
 const getScrollPos = (el = window) =>
-  ( {x: (el.pageXOffset !== undefined) ? el.pageXOffset : el.scrollLeft,
+  ({x: (el.pageXOffset !== undefined) ? el.pageXOffset : el.scrollLeft,
-   y: (el.pageYOffset !== undefined) ? el.pageYOffset : el.scrollTop} );
+    y: (el.pageYOffset !== undefined) ? el.pageYOffset : el.scrollTop});
 // getScrollPos() -> {x: 0, y: 200}
 ```

snippets/greatest-common-divisor-(GCD).md

@@ -5,6 +5,6 @@ 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
-const gcd = (x , y) => !y ? x : gcd(y, x % y);
+const gcd = (x, y) => !y ? x : gcd(y, x % y);
 // gcd (8, 36) -> 4
 ```

snippets/hamming-distance.md

@@ -5,6 +5,6 @@ Count and return the number of `1`s in the string, using `match(/1/g)`.
 
 ```js
 const hammingDistance = (num1, num2) =>
-  ((num1^num2).toString(2).match(/1/g) || '').length;
+  ((num1 ^ num2).toString(2).match(/1/g) || '').length;
 // hammingDistance(2,3) -> 1
 ```

snippets/initial-of-list.md

@@ -3,6 +3,6 @@
 Return `arr.slice(0,-1)`.
 
 ```js
-const initial = arr => arr.slice(0,-1);
+const initial = arr => arr.slice(0, -1);
 // initial([1,2,3]) -> [1,2]
 ```

snippets/initialize-array-with-range.md

@@ -5,6 +5,6 @@ You can omit `start` to use a default value of `0`.
 
 ```js
 const initializeArrayRange = (end, start = 0) =>
-  Array.apply(null, Array(end-start)).map( (v,i) => i + start );
+  Array.apply(null, Array(end - start)).map((v, i) => i + start);
 // initializeArrayRange(5) -> [0,1,2,3,4]
 ```

snippets/measure-time-taken-by-function.md

@@ -8,6 +8,6 @@ const timeTaken = callback => {
   const t0 = performance.now(), r = callback();
   console.log(performance.now() - t0);
   return r;
-}
+};
 // timeTaken(() => Math.pow(2, 10)) -> 1024 (0.010000000009313226 logged in console)
 ```

snippets/median-of-array-of-numbers.md

@@ -5,9 +5,9 @@ Return the number at the midpoint if `length` is odd, otherwise the average of t
 
 ```js
 const median = arr => {
-  const mid = Math.floor(arr.length / 2), nums = arr.sort((a,b) => a - b);
+  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
 ```

snippets/object-from-key-value-pairs.md

@@ -3,6 +3,6 @@
 Use `Array.reduce()` to create and combine key-value pairs.
 
 ```js
-const objectFromPairs = arr => arr.reduce((a,v) => (a[v[0]] = v[1], a), {});
+const objectFromPairs = arr => arr.reduce((a, v) => (a[v[0]] = v[1], a), {});
 // objectFromPairs([['a',1],['b',2]]) -> {a: 1, b: 2}
 ```

snippets/powerset.md

@@ -4,6 +4,6 @@ Use `Array.reduce()` combined with `Array.map()` to iterate over elements and co
 
 ```js
 const powerset = arr =>
-  arr.reduce( (a,v) => a.concat(a.map( r => [v].concat(r) )), [[]]);
+  arr.reduce((a, v) => a.concat(a.map(r => [v].concat(r))), [[]]);
 // powerset([1,2]) -> [[], [1], [2], [2,1]]
 ```

snippets/randomize-order-of-array.md

@@ -3,6 +3,6 @@
 Use `Array.sort()` to reorder elements, utilizing `Math.random()` to randomize the sorting.
 
 ```js
-const 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);
 // randomizeOrder([1,2,3]) -> [1,3,2]
 ```

snippets/scroll-to-top.md

@@ -6,10 +6,10 @@ Scroll by a fraction of the distance from top. Use `window.requestAnimationFrame
 ```js
 const scrollToTop = _ => {
   const c = document.documentElement.scrollTop || document.body.scrollTop;
-  if(c > 0) {
+  if (c > 0) {
     window.requestAnimationFrame(scrollToTop);
-    window.scrollTo(0, c - c/8);
+    window.scrollTo(0, c - c / 8);
   }
-}
+};
 // scrollToTop()
 ```

snippets/shuffle-array-values.md

@@ -6,7 +6,7 @@ Use `Array.sort()` to sort the elements of the original array based on the rando
 ```js
 const shuffle = arr => {
   let r = arr.map(Math.random);
-  return arr.sort((a,b) => r[a] - r[b]);
+  return arr.sort((a, b) => r[a] - r[b]);
-}
+};
 // shuffle([1,2,3]) -> [2, 1, 3]
 ```

snippets/sort-characters-in-string-(alphabetical).md

@@ -4,6 +4,6 @@ Split the string using `split('')`, `Array.sort()` utilizing `localeCompare()`,
 
 ```js
 const sortCharactersInString = str =>
-  str.split('').sort( (a,b) => a.localeCompare(b) ).join('');
+  str.split('').sort((a, b) => a.localeCompare(b)).join('');
 // sortCharactersInString('cabbage') -> 'aabbceg'
 ```

snippets/sum-of-array-of-numbers.md

@@ -3,6 +3,6 @@
 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);
+const sum = arr => arr.reduce((acc, val) => acc + val, 0);
 // sum([1,2,3,4]) -> 10
 ```

snippets/truncate-a-string.md

@@ -5,6 +5,6 @@ Return the string truncated to the desired length, with `...` appended to the en
 
 ```js
 const truncate = (str, num) =>
-  str.length > num ? str.slice(0, num > 3 ? num-3 : num) + '...' : str;
+  str.length > num ? str.slice(0, num > 3 ? num - 3 : num) + '...' : str;
 // truncate('boomerang', 7) -> 'boom...'
 ```