Why is isNaN(null) == false in JS?

Question

This code in JS gives me a popup saying \"i think null is a number\", which I find slightly disturbing. What am I missing?

Answer 1

I just ran into this issue myself.

For me, the best way to use isNaN is like so

isNaN(parseInt(myInt))

taking phyzome's example from above,

var x = [undefined, NaN,     'blah', 0/0,  null, 0,     '0',   1,     1/0, -1/0,  Number(5)]
x.map( function(n){ return isNaN(parseInt(n))})
        [true,      true,    true,   true, true, false, false, false, true, true, false]

( I aligned the result according to the input, hope it makes it easier to read. )

This seems better to me.