## split()函数无参情况时：
当split无参时，表示将调用者整个字符串存入到数组中。

// 将整个字符串存到数组中
value='za,we,ds,aw'
value.split(); ==>["za,we,ds,aw"]

## split()函数参数为空字符串时：

// 将字符串中每个字符单独存到数组中
value='za,we,ds,aw'
value.split(''); ==>["z","a",",","w","e",",","d","s",",","a","w"]

## split()函数参数为指定字符串时：

// 按照指定字符串截取转换为数组
value='za,we,ds,aw'
value.split(','); ==>["za","we","ds","aw"]

## reverse()函数：
将指定数组倒序排序并返回

value='za,we,ds,aw'
value.split(',').reverse(); ==>["aw","za","we","ds"]

## join()函数无参时：

将指定数组中全部数据用','逗号连接转换为一个字符串
value='za,we,ds,aw'
value.split(',').reverse().join(); ==>"aw,za,we,ds"

## join()函数参数为空字符串时：

将指定数组中全部数据转换为一个字符串
value='za,we,ds,aw'
value.split(',').reverse().join(''); ==>"awzaweds"

## join()函数参数有参时：

将指定数组中全部数据按照指定字符连接，并转成一个字符串
value='za,we,ds,aw'
value.split(',').reverse().join('+'); ==>"aw+ds+we+za"