What is the difference between $(document).ready(function() and $(function() ?

Question

So I know what this does:

$(document).ready(function(){
 // Your code here...
});

Now I have seen people doing this lately:

<script type="text/javascript"> 
$(function(){
 // Your code here...
});
</script>

Are these two ways of doing the same thing?

I see an anonymous function being declared inside a jquery selector here, but never actually being invoked, yet by the way the page runs it seems that this may just run on pageload.

• blockhead: Lately? This has been available for the last 5 years....
• LarsH: That's one of the things I dislike about jquery... in pursuit of brevity, it seriously sacrifices (re)discoverability. IIRC, $(...) can do at least three completely different things, depending on the type of the argument, and how do you look up such a thing? You can if you're familiar with the docs - and that's precisely the point. The language is designed for those who stay familiar with its details. </rant>
• LarsH: P.S. In this case, if you remember that $ is an alias for jQuery, you can look it up here: api.jquery.com/jQuery

Answer 1

yes, they're doing the same thing. the $() function wraps $(document).ready() when the parameter to the call is a single function object.

(Edited to reflect a question in comment)

• thirsty93: So whenever you use a jquery selector a quiet little document ready check is happening in the background?
• Alex Barrett: No, jQuery checks the type of the object passed to it and if it is a function it is bound to the document's ready event; if it's passed a string, it will do something else (like select DOM elements).

Answer 2

Yes, they are doing exactly the same thing.

$(function(){
 // Your code here...
});

is a shortcut for

$(document).ready(function(){
 // Your code here...
});