1、數組轉字符串 join

    var aArr = [1,2,2,2,2,3]
    var sStr = null;
    sStr = aArr.join("-");
    console.log(sStr)//1-2-2-2-2-3
    sStr = aArr.join("+");
    console.log(sStr)//1+2+2+2+2+3

2、字符串轉數組

    var sStr = "abc,abcd,aaa";
    var aArr = null;
    aArr = sStr.split(",")
    console.log(aArr)// ["abc", "abcd", "aaa"]
 

    aArr = sStr.split("")
    console.log(aArr)//["a", "b", "c", ",", "a", "b", "c", "d", ",", "a", "a", "a"]
    aArr = sStr.split("-")
    console.log(aArr)//["abc,abcd,aaa"]

    //字符串轉數組通過split參數切割成若幹個字符串，並以數組形式返回

3、將JSON字符串對象互轉 （註意是JSON字符串）

    var oObj = {
        name:‘北京‘,
        age:1800,
        value:
 
‘首都‘
    }
    var sStr = JSON.stringify(oObj);
    console.log(sStr) //{"name":"北京","age":1800,"value":"首都"}
    console.log(typeof sStr) //string

    var sJsonStr = ‘{"name":"北京","age":1800,"value":"首都"}‘
    var oJsonObj = JSON.parse(sJsonStr)
    console.log(oJsonObj) //{name: "北京", age: 1800, value: "首都"}
 

    console.log(typeof oJsonObj) //object

4、非字符串通過JSON.parse轉對象

var sString = ‘121212‘
    var sJsonString = JSON.parse(sString)
    console.log(sJsonString)//121212
    console.log(typeof sJsonString) //number

    var sString = ‘nanjign‘
    var sJsonString = JSON.parse(sString) //Uncaught SyntaxError: Unexpected token a in JSON at position 1

通過運行代碼得知，js對字符串能轉換就轉換為其他類型是數據。盡量不報錯，仁至義盡。

js字符串轉數組，轉對象方法