数组中的搜索方式

代码如下：

var TimeSheet:Array = ["00:00","00:30","01:00","01:30","02:00","02:30","03:00","03:30","04:00","04:30","05:00","05:30",
		     "06:00","06:30","07:00","07:30","08:00","08:30","09:00","09:30","10:00","10:30","11:00","11:30",
		     "12:00","12:30","13:00","13:30","14:00","14:30","15:00","15:30","16:00","16:30","17:00","17:30",
		     "18:00","18:30","19:00","19:30","20:00","20:30","21:00","21:30","22:00","22:30","23:00","23:30"];
var str:String="12:30";
var index:int = TimeSheet.indexOf(str);
trace(index) //输出25