Why do you need to invoke an anonymous function on the same line?

Question

I was reading some posts about closures and saw this everywhere, but there is no clear explanation how it works - everytime I was just told to use it...:

//          


        

Answer 1

When you did:

(function (msg){alert(msg)});
('SO');

You ended the function before ('SO') because of the semicolon. If you just write:

(function (msg){alert(msg)})
('SO');

It will work.

Working example: http://jsfiddle.net/oliverni/dbVjg/