ES6數組去重的常用方法

數組去重的常用方法匯總:

方法一:

[...newSet(test)];

　　

方法二:

Array.from()

　　

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

　　

方法三:

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

　　

方法四:

數組中對象去重;

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',
}
]


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;
},

 

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ES5:

方法一： (更新於2020年4月15日)：

思路：

• 1. 創建一個新的空數組,用來存放去重后的新數組.
• 2. 利用for循環循環遍歷需要去重的數組.
• 3. 利用indexOf()方法查詢遍歷出的數組在新數組中是否出現,如果出現:則繼續遍歷數組,如未出現:則利用push方法添加到新數組中.
• 4. 原數組循環遍歷完成后,組建一個已經去除重復的新數組.

 

  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);

 

歡迎issue！！！