In JavaScript, why does isNaN(" ") evaluate to false, but isNaN(" x") evaluate to true? I’m performing numerical operations on a text input field, and I’m checking if the field is null, "", or NaN. When someone types...

parseFloat("NaN") returns "NaN", but parseFloat("NaN") == "NaN" returns false. Now, that's probably a good thing that it does return false, but I don't understand how this is so. Did the JavaScript creat...

I have set up a js / three.js program for calculating cylinders by only two given values. The only calculation that is quite difficult happens when volume and surface are given. From both values I need to calculate the radius or the height. To rec...

I am developing a html page that takes date and displays day. I am using a formula called Zeller's congruence. But in JavaScript the formula returns the Result "NaN". I googled the problem. Couldn't figure out the solution. Here is t...

Take a look at this fiddle: http://jsfiddle.net/gD3ax/1/ or here's the full markup <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> <html xmlns=...

I'm grabbing a JSON obj from an external source. It appears as so: {"total":16231642,"totalamount":437442282.55} I set it as a global var, set it in the each function and then try to retrieve it outside of it, below. But i get...

Why is there an isNaN() function in JavaScript whilst isUndefined() must be written as: typeof(...) != "undefined" Is there a point I don't see? In my opinion its really ugly to write this instead of just isUndefined(testValue)....

Was playing around with some code to create an array of 0's and found that for only one value NaN was returned instead of 0. I get this in Chrome, Node, and Firefox. What's causing the second value to be NaN? var arr = new Array(32).join(...

I am trying to get the highest number from a simple array: data = [4, 2, 6, 1, 3, 7, 5, 3]; alert(Math.max(data)); I have read that if even one of the values in the array can't be converted to number, it will return NaN, but in my case, I hav...

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