数组转字符串,字符串转数组,对象转数组,数组转对象

数组转字符串

var arr = [1,2,3,4,'李明','jerry'];
arr.join()
//"1,2,3,4,李明,jerry"

arr.toString()
//"1,2,3,4,李明,jerry"

arr.join("")
//"1234李明jerry"

arr.join("-")
//"1-2-3-4-李明-jerry"

JSON.stringify(arr)
//"[1,2,3,4,"李明","jerry"]"

var x = JSON.stringify(arr)
JSON.parse(x)
//[1, 2, 3, 4, "李明", "jerry"]

字符串转数组

var x = "1-2-3-4-李明-jerry"
x.split("")
//["1", "-", "2", "-", "3", "-", "4", "-", "李", "明", "-", "j", "e", "r", "r", "y"]
x.split("-")
//["1", "2", "3", "4", "李明", "jerry"]

对象转数组

var x = {"name":"李明","age":23}

对象的键组成数组

Object.keys(x)
//["name", "age"]

对象的值组成数组

Object.values(x)
// ["李明", 23]

键值对组成的数组

Object.entries(x)
//[["name", "李明"],["age", 23]]

数组转对象

var arr =[1, 2, 3, 4, "李明", "jerry"]
{...arr}
//{0: 1, 1: 2, 2: 3, 3: 4, 4: "李明", 5: "jerry"}