Why is NaN not finite?

Question

Function Testing isFiniteI see that it NaNis an infinite number (even if it is not a number :-)).

isFinite(NaN) // returns false

What is the logic behind this? Why not the NaNend?

Answer 1

As Dave Newton said, NaN is not a number, and then you must consider that it is not limited and not infinite. The same thing happens to them:

NaN > 0  // false
NaN < 0  // false

You might want to read the following articles:

• https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/NaN
• https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/isFinite

Answer 2

... / .

Answer 3

Because an infinite number ... anyway a number. NaN is not a number in any possible sense.

This is like an error in the matrix.

Answer 4

The result of any arithmetic operation on NaN is NaN.

The result of any logical operation on NaN is false.

Answer 5

Final funds are able to be counted. It should return true or false for isFinite. I think it makes more sense for NaN to be infinite.