JS数组元素去重

一维数组去重

let arr = [1,2,3,4,5,4,,3,2,1]
let set = new Set()
arr.forEach((item)=> set.add(item))
let a = Array.from(set)
console.log(a) //[1,2,3,4,5]

二维数组去重

let arr = [[1,2], [2,3], [1,2]]
let a = []
arr.forEach((item)=> a[item]=item)
let b = []
for(let key in a){
      b.push(a[key])
}
console.log(b) //[[1,2], [2,3]]

数组元素类型不定

let arr = [
      {name: 'zhang', age:20},
      {name: 'liu', age: 18},
      {name: 'zhang', age:20}
]
let a=[]
arr.forEach((item)=> a[item.name]=item)
let b=[]
for(let key in a){
      b.push(a[key])
}
console.log(b) //[{name: 'zhang', age:20}, {name:'liu', age:18}]