[jQuery] Re: chaining and functions

[Michael Geary]

> I do not understand why
> 
> $('#content').empty().append("<b>hello</b>");
> 
> works, and this works
> 
> $('#content').empty().append(makeContent());
> 
> function makeContent(){
>               return "<b>hello</b>";
>               };

That works because it is exactly the same as this code:

    function makeContent(){
        return "<b>hello</b>";
    }

    var content = makeContent();

    $('#content').empty().append(content);

IOW, the () after makeContent cause that function to be called *before* the
append() call, and makeContent's *return value* is passed into append().

> and this
> 
> $('#content').empty().append( function() { return "<b>hello</b>" } );
> 
> does not produce any output?

That doesn't work because you are not calling the function any more, but
merely passing a *reference* to the function, i.e. the function itself, into
append(). append() doesn't expect to be passed a function.

IOW, that code is the same as:

    function makeContent(){
        return "<b>hello</b>";
    }

    $('#content').empty().append(makeContent);

Without the parens, makeContent is not called.

-Mike