Question

This is probably a nub question, but I don’t understand why this works:

<script type="text/javascript">
    alert(foo);
    function foo() { }
</script>

This alerts “function foo() { }”, but I expected the alert to be evaluated before the function foo was defined. Can someone explain what I don’t understand about parse/evaluation order or point me to a resource that does?

Answer 1

JavaScript, like PHP, tracks top-level function declarations before the code runs.
However, you can bypass the auto-function by using assignments:

var a = function a() { }