Hoisting between different files

Question

Is there a way to do functions and variable hoisting between source code present in different files? That is, something like

//Inside firstfile.js
foo === "bar" //should return true

and

//Inside secondfile.js
function bar() {
    this.foo = "bar";
}

I guess this is not possible, as different files as parsed and executed separately and in order by most javascript engines, but I do not know for sure.

I don't know even if this is in the spec from ECMA, as the parsing of different files is not really part of the language.

Answer 1

I originally thought this was a more interesting question than it actually appears. The answer to the question I thought this was is that each <script> element represents a separate Program, each separate Program is parsed and (crucially) executed before anything happens to the next Program, therefore the effects of hoisting can only be seen within a single Program.

For example, within a single script:

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

... alerts "function" because the function declaration is hoisted, but splitting the two lines into separate <script> elements changes this:

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

... alerts "undefined", because the first script is executed before the second script is even parsed.