1 //返回指定位置字符charAt：
2 var mystr="I love you!";
3 console.log(mystr.charAt(3));
4 //"o"
1 //返回字符串首次出现位置indexOf：
2 var mystr="I love you!";
3 console.log(mystr.indexOf("o"));
4 //3
5 console.log(mystr.indexOf('o',4));
6 //-1
1 //截取字符串substring:
2 var mystr='ceshi yixia'；
3 console.log(mystr.substring(2,2));
4 //""
5 console.log(mystr.substring(2,5));
6 //"shi"
7 console.log(mystr.substring(5,2));
8 //"shi"
1 //指定截取长度substr:
2 var mystr="Hello World!";
3 console.log( mystr.substr(6,5));
4 //World
5 console.log( mystr.substr(0,5));
6 //Hello
1 //字符串反序
2 var str="i love you";
3 str.split('').reverse().join('');
4 //uoy evol i
