<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>数组部分方法，es6</title>
<style type="text/css">
</style>
</head>
<body>
</body>
</html>
<script>
let arr = [1,2,3,5,5,2]
// 1.数组合并
// let arr1 = [6,8,9]
// console.log(arr.concat(arr1)) //[1, 2, 3, 5, 5, 2, 6, 8, 9]
// 2.reduce计算数组元素之和
// let arr_ = arr.reduce((pre,cur) => pre+cur)
// console.log(arr_) //18
// 3.reduce计算数组元素出现次数
// let arr_ = arr.reduce((pre,cur) => {
// if(cur in pre){
// pre[cur]++
// }else{
// pre[cur] = 1
// }
// return pre
// },{})
// console.log(arr_) //{1: 1, 2: 2, 3: 1, 5: 2}
// 4.reduce去重
// let arr_ = arr.reduce((pre,cur) => {
// if(!pre.includes(cur)){
// return pre.concat(cur)
// }else{
// return pre
// }
// return pre
// },[])
// console.log(arr_) //[1, 2, 3, 5]
</script>
