JavaScript数组去重方法总结

Posted 2020-12-31 detanx

一、双重遍历去重

function onlyFigure(arr) {
      let newarr = [];
      const length = arr.length
      for (let i = 0; i < length; i++) {
        for(let j = i + 1; j < length; j++) {
          if(arr[i] === arr[j]) {
              i++;
              j=i;
          }
        }
        newarr.push(arr[i])
      }
      console.log(arr);
    }
    onlyFigure([0,0,1,2,4,2,1,6,5]);

　　
二、原数组下标indexOf去重

function onlyFigure(arr) {
      let newarr = [];
      for (let i = 0; i < arr.length; i++) {
        if(arr.indexOf(arr[i]) == i) {
          //console.log(arr.indexOf(arr[i]));
          arr.push(arr[i]);
        }
      }
      console.log(newarr);
    }
    onlyFigure([0,0,1,2,4,2,1,6,5]);

　　

三、新数组indexOf去重

function only(arr) {
      let newarr = [];
      let len = arr.length;
      for(let i = 0 ; i < len ; i ++ ) {
        if(newarr.indexOf(arr[i]) === -1) {
          newarr.push(arr[i])
        }
      }
      return newarr
    }

　　

四、es6 Set去重

function onlyNum(arr) {
      return Array.from(new Set(arr))
    }