数组嵌套对象去重

1.简单数组去重

 const arr1 = [1,2,3,1]
 [...new Set(arr1)] 

2.复杂数组去重

var arr = [{
key: '01',
value: '乐乐'
}, {
key: '02',
value: '博博'
}, {
key: '03',
value: '淘淘'
},{
key: '04',
value: '哈哈'
},{
key: '01',
value: '乐乐'
}];

const obj = {};
const newarr =arr.filter(item =>
obj[item.key] ? '' : (obj[item.key] = true),
);