JavaScript数组与字符串相互转换 join、split

字符串转数组

let str = 'string'
let arr = []

arr = str.split() // arr = ['string']  直接转为数组[0]项目
arr = str.split('') // arr = ['s','t','r','i','n','g']  直接以单个字符分隔成数组对应下标项

str = 's-t-r-i-n-g'
arr = str.split('-') // arr = ['s','t','r','i','n','g']  以'-'分隔字符串 

数组转字符串

let arr = [1,2,3,4,5]
let str = ''

str = arr.join('') // str = '1,2,3,4,5' // 默认以逗号隔开
str = arr.join('-') // str = '1-2-3-4-5' // 以'-'隔开