Comparing NaN values for equality in Javascript

Question

I need to compare two numeric values for equality in Javascript. The values may be NaN as well. I\'ve come up with this code:

if (val1 == val2 |         


        

Answer 1

NaN is never equal to itself no matter the comparison method, so the only more concise solution for your problem that I can think of would be to create a function call with a descriptive name for doing this rather special comparison and use that comparison function in your code instead.

That would also have the advantage of localizing changes to the algorithm the day you decide that undefined should be equal to undefined too.