多维数组转变为一维数组

1·join和split

join将数组拼接为字符串  split将字符串转变为数组

结果的元素为字符串，可通过map遍历处理每一项

1     let temp = [1, [2, 3], [4, 5, [6, 7]]];
2     let res = temp.join(',').split(',')
3     let res2 = res.map((val, idx) => {
4       return Number(val)
5     })
6     console.log(res)
7     console.log(res2)

 2· 递归

 1 　　 let temp = [1, [2, 3], [4, 5, [6, 7]]];
 2     let target = []
 3     let fn = (source) => {
 4       for (let i of source) {
 5         if (Array.isArray(i)) {
 6           fn(i)
 7         } else {
 8           target.push(i)
 9         }
10       }
11     }
12     fn(temp)
13     console.log('递归多维数组', target)

 3·多维数组concat

1     let array = ['1', 2, [3, 4, [5, 6]], 7];
2     let res2 = array.reduce((pre, cur) => {
3       return pre.concat(cur)
4     }, [])
5     console.log('多维数组concat', res2)

 所以：concat只适合二维数组

1     let array = ['1', 2, [3, 4], 7];
2     let res2 = array.reduce((pre, cur) => {
3       return pre.concat(cur)
4     }, [])
5     console.log('多维数组concat -- 二维', res2)