//charAt和charCodeAt分别返回指定位置处的字符和字符对应的unicode码 var str:String="abcdefg"; var str2=str.charAt(1); var str3=str.charCodeAt(1); trace(str2); //b trace(str3); //98
fromCharCode是个静态方法,根据unicode返回字符
var str:String=String.fromCharCode(97,98); trace(str); //ab