Is there a function to test if a String variable is a number value?

Question

Is there a way to test a string, such as the one below to see if it's an actual number value?

var theStr:String = '05';

I want to differentiate between the string value above and one such as this:

var theStr2:String = 'asdfl';

Thanks!

Answer 1

Yes use isNaN function to test if it the String is a valid Number:

var n:Number=Number(theStr);
if (isNaN(n)){
 trace("not a number");
} else {
 trace("number="+n);
}

Answer 2

You must cast to Number to get is NaN. If you use int letters can be cast to 0.