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"); // 14

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);//2
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);//2.