数组去重

//数组去重

let arr = [
 {key: '01',value: '貂蝉'},
 {key: '02',value: '吕布'},
 {key: '03',value: '大乔'},
 {key: '04',value: '小乔'},
 {key: '01',value: '貂蝉'}
];
let arr2 = [];
let obj = {};
arr.forEach((item) =>{
 if(!obj[item.key]){//对象中没有这一项时执行
  arr2.push(item);//将这一项增加到新数组中
  obj[item.key] = true;//
 }
});
console.log(arr2);
使用jquery中的each去重

//数组去重
let arr3 = [
{ key: "01", value: "貂蝉" },
{ key: "02", value: "吕布" },
{ key: "03", value: "大乔" },
{ key: "04", value: "小乔" },
{ key: "01", value: "貂蝉" }
];
let o = {};
let arr4 = [];
$.each(arr3, function(i, val) {
if(!o[val.key]){
arr4.push(val);
o[val.key] = true;
}
});
console.log(arr4);