JavaScript小技巧

const array=[1,2,3,4,5,2,3,4,5,6]
const arrayFilter =[...new Set(array)];
console.log(arrayFilter) //

1
2
3
4

    var example = "potato potato";
    console.log(example.replace(/pot/, "tom")); 
    // "tomato potato"
    console.log(example.replace(/pot/g, "tom")); 
    // "tomato tomato”

1
2
3
4
5
6

    var my_list = [1, 2, 3, 4, 5, 6, 7, 8, 9];
    console.log(my_list.sort(function() {
        return Math.random() - 0.5
    })); 
    // [4, 8, 2, 9, 1, 3, 6, 5, 7]

1
2
3
4
5

	var entries = [1, [2, 5], [6, 7], 9];    
  var flat_entries = [].concat(...entries); 
  // [1, 2, 5, 6, 7, 9]

1
2
3

 function person (x,y) {
   return {
     x:x,
     y:y
   }
 }

1
2
3
4
5
6

  function person (x,y) {
   return {
     x,
     y
   }
 }

1
2
3
4
5
6
7

  function person ( config ){
    if( config.a ) { ... }
    if( config.b ) { ... }
    if( config.c ) { ... }
  }


  function person ( { a , b , c } ) {
    if(a){ ... }
    if(b){ ... } 
    if(c){ ... }
  }

1
2
3
4
5
6
7
8
9
10
11
12

  let obj={'0':'aaa','1':'bbb',length:2}

  console.log(Array.from(obj)) 
  // ['aaa','bbb']

1
2
3
4

  let args=Array.from(arguments)

1

  let list=[1,3,5]
  Array.form( list , x = > x + 1 )
  //[2,4,6]

  等同于
  Arrar.form(list).map(item=>item+1)
  //[2,4,6]

1
2
3
4
5
6
7

  [1,2,3,4,5,6].fill('a')
  // [a,a,a,a,a,a]

  new Array(3).fill(11)
  // [11,11,11]

1
2
3
4
5

  [1,2,3,4,5,6].fill('a',2,4)
  // [1,2,a,a,5,6]

1
2

  [1,2,3,4,5,6].find((item,index,array)=>{
    return item>5
  })

  // 6

1
2
3
4
5
6

  [1,2,3,4,5,6].findIndex((item,index,array)=>{
    return item>3
  })

  // 3

1
2
3
4
5
6

 if(arrar.indexof('a')>-1){

 }

1
2
3

 [NaN].indexOf(NaN)
 // -1

1
2

 [NaN].includes(NaN)
 // true

1
2

葵花宝典

Choose mode

JavaScript小技巧

# 过滤

# 全部替换

# 随机排列数组元素

# 展开多维数组

# 简写属性

# 解构赋值

# es6常用数组方法

# Array.from

# fill

# find和findIndex

# includes