var myStr = "I,Love,You,Do,you,love,me";

 var substrArray = myStr .split(","); // ["I", "Love", "You", "Do", "you", "love", "me"];

 var arrayLimited = myStr .split(",", 3); // ["I", "Love", "You"];

 第一个函数：indexOf()，它从字符串的开头开始查找，找到返回对应坐标，找不到返回-1。如下：

 var myStr = "I,Love,you,Do,you,love,me";

 var index = myStr.indexOf("you"); // 7 ,基于0开始,找不到返回-1

 第二个函数：lastIndexOf()，它从字符串的末尾开始查找，找到返回对应坐标，找不到返回-1。如下：

 var myStr = "I,Love,you,Do,you,love,me";

 var index = myStr.lastIndexOf("you"); //

var myStr = "I,love,you,Do,you,love,me";

var replacedStr = myStr.replace("love","hate");//"I,hate,you,Do,you,love,me"

//正则替换

var myStr = "I,love,you,Do,you,love,me";

var replacedStr = myStr.replace(/love/g,"hate");//"I,hate,you,Do,you,hate,me"

 var myStr = "I,love,you,Do,you,love,me";

 var subStr = myStr.slice(1,5);//",lov"

 var myStr = "I,love,you,Do,you,love,me";

 var pattern = /love/;

 var result = myStr.match(pattern);//["love"]
//var result = pattern .exec(myStr);//["love"]  或者是

 console.log(result .index);//

 console.log(result.input );//I,love,you,Do,you,love,me

 var myStr = "I,love,you,Do,you,love,me";

 var pattern = /love/;

 var result = myStr.search(pattern);//.