js字符串常用操作

1.字符串分割

 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"];

2.查询子字符串

 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"); //

3.字符串替换

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"

4.字符串切割和提取

 var myStr = "I,love,you,Do,you,love,me";
 var subStr = myStr.slice(1,5);//",lov"

5.字符串匹配（exec相反）

 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

也可以用search

 var myStr = "I,love,you,Do,you,love,me";
 var pattern = /love/;
 var result = myStr.search(pattern);//.