Comparision of Numbers doesn't happen as expected, NaN behaviour

Question

I have two variables;

var x = '23b';
var y = '23a';

Now i have a logic which will compare, if they're equal i want to perform something

Note: Both when compared, if both are NaN still they should pass the condition

i have tried using this

if (Number(x) == Number(y))

This returns false even though both are NaN

Possible duplicate of [Comparing NaN values for equality in Javascript](http://stackoverflow.com/questions/8965364/comparing-nan-values-for-equality-in-javascript) — codersl, Jan 19 '17 at 09:52

score 0 · Answer 1 · answered Jan 19 '17 at 09:54

0

Why Number?

just use parseInt

if (parseInt(x, 10) == parseInt(y, 10))

The behaviour on NaN is misleading

just console this NaN == NaN

You will get value as false

answered Jan 19 '17 at 09:54

Kiran Shinde

Afnan Ahmad · Answer 2 · 2017-01-19T10:03:53.750

0

You can Use isNAN

var x = '23b';
var y = '23a';
if(isNAN(x) && isNAN(y))
alert("both are NAN");

edited Jan 19 '17 at 10:03

answered Jan 19 '17 at 09:55

Afnan Ahmad

That test is true if both are numbers, irrespective if they are equal or not. – traktor Jan 19 '17 at 09:56
@Traktor53 yes thats true this will compare if both are NAN and I think he has the same question. – Afnan Ahmad Jan 19 '17 at 10:01
To test if both are NaN: `if(isNaN(x) && isNaN(y))` – traktor Jan 19 '17 at 10:02
@Traktor53 ohh fixed it :D. – Afnan Ahmad Jan 19 '17 at 10:04

score 0 · Answer 3 · answered Jan 19 '17 at 10:10

0

var x = '23b';
var y = '23a';
console.log(parseFloat(x)===parseFloat(y));

answered Jan 19 '17 at 10:10

LellisMoon

score 0 · Answer 4 · edited Jan 17 '18 at 13:07

0

Try using Object.is()

var x = '23b';

var y = '23a';

Object.is(Number(x),Number(y)); => true

edited Jan 17 '18 at 13:07

Lotus91

answered Jan 17 '18 at 12:24

Anant

4 Answers4