mootools - scandals, intrigues, investigations

Question

JavaScript

Maybe I'm stupid, maybe I'm swollen by 7 in the morning ... But please explain to me someone why in this code:

window.addEvent('domready', function() {
    console.log(Number.random(5-20));
    alert(Number.random(5,20));
});

In the first case, it returns NaN, and in the second case, it returns a number. WHY??? =(

Answer 1

console.log(Number.random(5-20));
change the minus to a comma. Sleep at night ;)

Answer 2

WHAT DOES MOOTOOLS DO?????