js字符串操作

字符串切割和提取

1、slice()函数：

var mystr="hello world!";
var sliceStr1=mystr.slice(-3);    //ld!
var sliceStr2=mystr.slice(-3,-1);    //ld
var sliceStr3=mystr.slice(3);    //lo world!
var sliceStr4=mystr.slice(3,7);    //lo w

2、substring()函数：

var mystr="hello world!";
var sliceStr1=mystr.substring(3);    //lo world!
var sliceStr2=mystr.substring(3,7);    //lo w

3、substr()函数：

var mystr="hello world!";
var sliceStr1=mystr.substr(3);    //lo world!
var sliceStr2=mystr.substr(3,7);    //lo wo

字符串去空格

var mystr="     hello world      ";  
var trimStr=mystr.trim();    //hello world

字符串替换

var mystr="wozaijinxingzifuchuantihuancaozuo,zifuchuantihuano";
var replaceStr=mystr.replace("zifuchuan"," ");    //wozaijinxing tihuancaozuo,zifuchuantihuano
var replaceStr=mystr.replace(/zifuchuan/," ");    //wozaijinxing tihuancaozuo,zifuchuantihuano
var replaceStr=mystr.replace(/zifuchuan/g," ");    //wozaijinxing tihuancaozuo, tihuano

字符串分割

将字符串进行拆分返回一个新的数组

var mystr="qingchenghuwoguoxiansheng,woaishenghuo,woaiziji";
var arr1=mystr.split(",");    //["qingchenghuwoguoxiansheng","woaishenghuo","woaiziji"];
var arr2=mystr.split("");        //["q","i","n","g","c","h","e","n","g","h","u","w","o","g","u","o","x","i","a","n","s","h","e","n","g",",","w","o","a","i","s","h","e","n","g","h","u","o",",","w","o","a","i","z","i","j","i"];

split()的第二个参数，表示返回的字符串数组的最大长度

var mystr="qingchenghuwoguoxiansheng,woaishenghuo,woaiziji";
var arr1=mystr.split(",",2); //["qingchenghuwoguoxiansheng","woaishenghuo"];
var arr2=mystr.split("",8); //["q","i","n","g","c","h","e","n"];