<html>
<head>
<script type="text/javascript"> //创建
var str = "aaafga";
var str1 = new String("aa");
var str2= String("aaasdrf"); //属性length
alert(str.length); //方法charAt()
alert(str2.charAt(3));//s //方法concat(str1,str2...）
alert(str.concat("dfa","55454")); //方法indexOf
alert(str.indexOf("a",1));//1 // 方法replace（）;
alert(str.replace("a","k"));//kaafga //方法 split（）; var st = "1-2-3-5-4-1-2";
var v = st.split("-");
alert(v.length);//7
alert(v[0]);//1 //
</script> </head>
<body>
this is my file
</body>
</html>