Some frequently used ES6 code snippets

Below are a list of ES6 code snippets which are used frequently. Hope that it will be helpful.

1. Shuffle array elements

let arr = [67, true, false, '55']
arr = arr.sort(() => 0.5 - Math.random())
console.log(arr)
// [ '55', 67, false, true ]

2. Remove characters which are not numbers

const str = 'xieyezi 23213 is 95994 so hansome 223333'
const numbers = str.replace(/\D/g, '')
console.log(numbers)
// 2321395994223333

3. Reverse sequence or words

const sentence = 'xieyezi js so handsome, lol.'
const reverseSentence = reverseBySeparator(sentence, "")
console.log(reverseSentence);
// .lol ,emosdnah os sj izeyeix

const reverseEachWord = reverseBySeparator(reverseSentence, " ")
console.log(reverseEachWord)
// izeyeix sj os ,emosdnah .lol

function reverseBySeparator(string, separator) {
  return string.split(separator).reverse().join(separator)
}

4. Convert number to binary or hex decimal

const num = 45
num.toString(2)
num.tostring(16)

5. Merge objects

const city = {
  name: 'Chongqing',
  population: '1,234,567,890'
}
const location = {
  longitude: '116.4',
  latitude: '39.9'
}
const fullCity = { ...city, ...location }
console.log(fullCity)
// {
//   name: 'Chongqing',
//   population: '1,234,567,890',
//   longitude: '116.4',
//   latitude: '39.9'
// }

6. === vs ==

// ==   ->  type conversion compariosn
// ===  ->  non-type conversion comparison

0 == false // true
0 === false // false
1 == "1" // true
1 === "1" // false
null == undefined // true
null === undefined // false

7. Assignment to variables from object properties

const forest = {
  location: 'Sweden',
  animals: 3,
  animalsTypes: ['Lions', 'Tigers', 'Bears'],
};

const { location, animals, animalsTypes } = forest;
const [lions, tigers, bears] = animalsTypes;

console.log(location); // Sweden
console.log(animals); // 3
console.log(lions); // Lions
console.log(tigers); // Tigers
console.log(bears); // Bears

8. Swap values of variables

let bears = 'bears'
let tigers = 'tigers'
[bears, tigers] = [tigers, bears]
console.log(bears) // tigers
console.log(tribes) // bears

9. Check whether one string is reversion of another string

const isReversed = (str1, str2) => {
  const normalize = (str) =>
    str.toLowerCase()
    .normalize('NFD')
    .split('')
    .reverse()
    .join('')
  return normalize(str1) === str2
}
console.log(isReversed('anagram', 'margana')) // true
console.log(isReversed('rac', 'car')) // true

10. Freeze an object

const octopus = {
  tentacles: 8,
  color: 'blue',
}
Object.freeze(octopus)
octopus.tentacles = 10 // Error, will not update
console.log(octopus) // { tentacles: 8, color: 'blue'}

11. Remove duplicated elements in array

const animals = ['bears', 'lions', 'tigers', 'bears', 'lions']
const unique = (arr) => [...new Set(arr)]

console.log(unique(animals)) // [ 'bears', 'lions', 'tigers' ]

12. Convert RGB to Hex format

const rgbToHex = (r, g, b) => {
  const toHex = (num) => {
    const hex = num.toString(16)
    return hex.length === 1 ? `0${hex}` : hex
  }
  return `#${toHex(r)}${toHex(g)}${toHex(b)}`
}
console.log(rgbToHex(46, 32, 67)) // #2e2043

13. Get max or min from array

const nums = [1, 2, 3, 4, 5, -3, 99, -45, -1]
const max = Math.max(...nums)
const min = Math.min(...nums)
console.log(max) // 99
console.log(min) // -45

14. Remove false values

const nums = [1, 0 , undefined, null, false];
const truthyNums = nums.filter(Boolean);
console.log(truthyNums) // [1]

15. Return default value if undefined or null

const nullval = null
const emptyString = ''
const someNum = 13

const a = nullval ?? 'A default'
const b = emptyString ?? 'B default'
const c = SomeNum ?? 'C default'

console.log(a) // A default
console.log(b) // '' // empty string != undefined or null
console.log(c) // 13

Reference: https://github.com/xieyezi/vuepress-blog/blob/master/docs/front-end/ES6-20%E4%B8%AA%E7%BB%8F%E5%B8%B8%E4%BD%BF%E7%94%A8%E7%9A%84%E6%8A%80%E5%B7%A7.md