<!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>