Bloodyaugust Bloodyaugust - 5 months ago 40
Javascript Question

In JavaScript, why does zero divided by zero return NaN, but any other divided by zero return Infinity?

It seems to me that the code

console.log(1 / 0)


should return
NaN
, but instead it returns
Infinity
. However this code:

console.log(0 / 0)


does return
NaN
. Can someone help me to understand the reasoning for this functionality? Not only does it seem to be inconsistent, it also seems to be wrong, in the case of
x / 0
where
x !== 0

Answer

Because that's how floating-point is defined (more generally than just Javascript). See for example:

Crudely speaking, you could think of 1/0 as the limit of 1/x as x tends to zero. And 0/0 has no reasonable interpretation at all, hence NaN.