please help, JavaScript question?

Question

var num = prompt('Enter a number!');

if (num > 0) {
alert('Your number is positive!')
} else if (num < 0) {
alert('Your number is negative')
} else if (num == 0) {
alert('The number is 0')
} else if (num === '' || num === null) {
alert('You didn\'t enter a number!')
} else {
alert('That is not a number!')
};

The empty string isn't running in this case when I put num == 0 before the num === '' like I have here but the (num === null) is running.. When I press enter on the empty string, it says "The number is 0." It only runs when I put num == 0 after the num === ''. Does order really matter in this case?

Answer 1

Maybe
parseInt(num) == 0

Answer 2

Change code to
num ===0

== check value with autoconvert (empty string equaves 0 if vavue converts to INT)
=== check type variables, after check value

Answer 3

When I changed it to num === 0 and typed in 0 in the prompt, it switched to "That is not a number!" Could it be the operator precedence maybe? the empty string works when I put the (num == 0) after the (num === '' || num === null)