Explanation of .sort in JavaScript

Question

I have what may seem to be a basic question about the .sort method in Javascript.

I just need a little more "down-to-earth" explanation about how this works:

If I have an array:

var myArray = [40, 50, 30, 70];

I want to sort myArray from smallest to largest, I would do:

myArray.sort(function(a,b) {
    return a-b;
});

So, stepping through that...

• 40 - 50 = -10 ... so since the value -10 is less than 0.. keep as is.
• 50 - 30 = 20 ... so since the value 20 is greater than 0.. rearrange array to:

[40,30,50,70].

So, once the rearrangement is done.. I assume does the sort method start over?

Sorry, if this is super basic, but just curious.. maybe I'm missing something that happens.