简朴数组去重:
{
const a = [1, 3, 4, 1, 5, 2, 6, 7, 8, 3]
const b = a.filter((item, index, self) => self.indexOf(item) === index)
console.log(b) //[1, 3, 4, 5, 2, 6, 7, 8]
}
实例1依据indexOf去重,indexOf的优点就是返回的是初次涌现的位置,如许背面纵然涌现的值一样,也只能返回第一次涌现的索引,固然这个只适用于简朴的数组
对象数组去重:
const objArr = [{
name: '称号1'
},{
name: '称号2'
},{
name: '称号3'
},{
name: '称号1'
},{
name: '称号2'
}]
const obj = {}
const newObjArr = []
for(let i = 0; i < objArr.length; i++){
if(!obj[objArr[i].name]){
newObjArr.push(objArr[i]);
obj[objArr[i].name] = true
}
}
console.log(newObjArr)
效果为:
[{
name: '称号1'
},{
name: '称号2'
},{
name: '称号3'
}]
还可以用reduce来处置惩罚,以下:
const objArr = [{
name: '称号1'
},{
name: '称号2'
},{
name: '称号3'
},{
name: '称号1'
},{
name: '称号2'
}]
const obj = {}
const newObjArr = objArr.reduce((prev, curr)=>{
obj[curr.name] ? true : obj[curr.name] = true && prev.push(curr);
return prev
}, [])
console.log(newObjArr)
效果为:
[{
name: '称号1'
},{
name: '称号2'
},{
name: '称号3'
}]
两个数组之间去重:
var arr3 = [{
id: 1,
name: 'lily'
}, {
id: 2,
name: 'hz'
}, {
id: 3,
name: '123'
}, {
id: 4,
name: '321'
}, {
id: 5,
name: 'aa'
}]
var other = [{
id: 1,
name: 'lily'
}, {
id: 2,
name: 'hz'
}]
isOther = (x, arr) =>{
for(var i = 0;i<arr.length;i++){
if(x === arr[i].id){
return true;
}
}
return false;
}
console.log(arr3.filter((item)=>!isOther(item.id, other)));
效果为:
[{
id: 3,
name: '123'
}, {
id: 4,
name: '321'
}, {
id: 5,
name: 'aa'
}]
上面例子中,在数组arr3去撤除跟数组isOther中雷同的元素,把不存在在isOther数组中的元素挑选出来