ES6数组去重的常用方法

数组去重的常用方法汇总:

方法一:

?

1	[...newSet(test)];

　　

方法二:

?

1	Array.from()

　　

?

1 2	const test = ['q', 'w', 'e', 'q', 'u', 'p'] Array.from(new Set(test))

　　

方法三:

?

1 2 3 4

function unique(arr) {     const res = new Map();     return arr.filter((a) => !res.has(a) && res.set(a, 1)) }

　　

方法四:

数组中对象去重;

?

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34

let test = [ {   imageId: '1',   imageUrl: 'https://raw.githubusercontent.com/perfectSymphony/vue-admin/master/src/assets/logo.png', }, {   imageId: '1',   imageUrl: 'https://raw.githubusercontent.com/perfectSymphony/vue-admin/master/src/assets/logo.png', }, {   imageId: '2',   imageUrl: 'https://raw.githubusercontent.com/perfectSymphony/vue-admin/master/src/assets/logo.png', }, {   imageId: '3',   imageUrl: 'https://raw.githubusercontent.com/perfectSymphony/vue-admin/master/src/assets/logo.png', }, {   imageId: '3',   imageUrl: 'https://raw.githubusercontent.com/perfectSymphony/vue-admin/master/src/assets/logo.png', }, {   imageId: '4',   imageUrl: 'https://raw.githubusercontent.com/perfectSymphony/vue-admin/master/src/assets/logo.png', } ]<br><br> objTrim: function(){     let obj = {};     this.test= this.test.reduce((cur,next) => {          obj[next.imageId] ? "" : obj[next.imageId] = true && cur.push(next);          return cur;     },[]);    return this.test; },

 

------------------------------------------------------------------------------------------------------------------------------------------------

ES5:

方法一： (更新于2020年4月15日)：

思路：

• 1. 创建一个新的空数组,用来存放去重后的新数组.
• 2. 利用for循环循环遍历需要去重的数组.
• 3. 利用indexOf()方法查询遍历出的数组在新数组中是否出现,如果出现:则继续遍历数组,如未出现:则利用push方法添加到新数组中.
• 4. 原数组循环遍历完成后,组建一个已经去除重复的新数组.

 

  var arr = [1,3,4,5,6,7,4,3,2,4,5,6,7,3,2];
  function find(){
    var newArr = [];
    for (var i = 0; i < arr.length; i++) {
      if (newArr.indexOf(arr[i]) == -1 ) {
        newArr.push(arr[i]);
      }
    }
    document.write(newArr);
  }
  find(arr);

 

欢迎issue！！！