Parseint Nan Detection Not Working

[higuy001]

Code:

function gmn(event) {var myNum = Math.floor(Math.random()*101);changeText("lo", "0");changeText("hi", "100");changeText("ans", myNum);}function changeText(text, withh) {var textFieldToChange = document.getElementById(text);var newTextFieldText = withh;					textFieldToChange.value = newTextFieldText;}function getText(text) {var textAreaValue = document.getElementById(text);return parseInt(textAreaValue.value);}function pInt(thing) {return parseInt(thing);}function alerttext(event) {var gess = getText("guess");gess = pInt(gess);var an = getText("ans");an = pInt(an);//NaN detection: \/if (gess == "NaN") {alert("bad");} else {alert(gess);if (gess < an) {changeText("lo", gess);} else if (gess > an) {changeText("hi", gess);}}changeText("guess", "");}function winn() {alert("YouWin!");}

For some reason, when I start it, enter a number, and hit guess, I get an alert "NaN" which means that the NaN detection didn't work correctly.Does anyone know why?HiGuy

[Ingolme]

"NaN" is not a string.If you want to check if something is a number you can use regular expressions:

if(/\D/.test(gess)) {  alert("bad");} else {

[higuy001]

Oh. Never thought of that. (Never heard of it either.)But it works!Thanks!HiGuy

[justsomeguy]

You can also use isNaN.

var x = "abc";x = parseInt(x, 10);if (isNaN(x)){  alert("not a number");}