How to make callback?

Question

JavaScript

I can’t understand how the callback is done correctly, it’s already the second day, well, I’m not catching up with it. Please help me with my code, how to do it right - first we display AAAAA then BBBBB. First we make the one function, then when it completes we execute two....

<script type="text/javascript">


var one = function(callback)
{

setTimeout('document.write("<h1>AAAAAAAAAAAAAAAA</h1>")', 1000);
callback;
}


var two = function()
{
document.write("<h1>BBBBBBBBBBBBBBBBB</h1>")
}

one(two);

</script>

Answer 1

Well, CALL callback is the same method. Parentheses...
Well, because of the timers, you will first have BBB, and then AAA. Why callbacks are here is not clear, but probably it should be so.