平时小记
1、数组去重
let arr = [1,3,1,2,3,2,5,6,2,2,23,2,1,3]
let brr= Object.values(arr.reduce((cur,next)=>{
console.log(cur)
if(!cur[next]){
cur[next] = next
}
return cur
},{}))
或者
arr = [...new Set(arr)]
2、计算数组中每个元素出现的次数
let arr = [1,3,1,2,3,2,5,6,2,2,23,2,1,3]
let obj = arr.reduce((cur,next)=>{
console.log(cur)
if(!cur[next]){
cur[next] = 1
}else {
cur[next] = cur[next]+1
}
return cur
},{})
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