数组去重的两种方式

来源：互联网发布：余佳文知乎编辑：程序博客网时间：2024/05/20 19:47

/*第一种方式    var hash ={     key :value,     "hello":true,     "node":true,     "world":true     };*/    function unique() {        var arr = ["hello","world","node","hello","node","node","node","hello","world","momo"];        var result = [], hash = {};        for (var i = 0, elem; (elem = arr[i]) != null; i++) {            if (!hash[elem]) { // . []                result.push(elem);                hash[elem] = true;            }        }        return result;    }    unique();    console.timeEnd("tag1");    console.time("tag2");//第二种方法    function quchong(){        var arr = ["hello","world","node","hello","node","node","node","hello","world","momo"];        var arr2 =[];        for(var i=0;i<arr.length;i++){            if(arr2.indexOf(arr[i]) <0){                arr2.push(arr[i]);            }        }        return arr2;    }    quchong();    console.timeEnd("tag2");    console.time("unique");    console.timeEnd("unique");    console.time("quchong");    console.timeEnd("quchong")

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