Javascript Redefine Infinity, NaN, Or "" As 0

I have a javascript calculator which accepts user input, does some math and writes the result to the input field '#theResult' Since '#theResult' updates on keyup, there are times w

Solution 1:

You've used theResult === 0 where you should have used theResult = 0.

The === is for comparisons. When you want to change the value of a variable, you use the assignment operator =.

Like @zzzzBov said, the simplest thing to do is replace the whole thing with

 theResult = isFinite(theResult) && theResult || 0; // updated

That glosses over the subtleties of NaN however; if the user is finished and the result really is NaN, showing that as 0 is not really correct.