What is a practical use for a closure in JavaScript?

itemprop="text">

I'm href="http://jsbin.com/ojuxo/edit" rel="noreferrer">trying my hardest to
wrap my head around JavaScript closures.

I get
that by returning an inner function, it will have access to any variable defined in its
immediate parent.

Where would this be useful to
me? Perhaps I haven't quite got my head around it yet. Most of the href="http://blog.morrisjohns.com/javascript_closures_for_dummies.html"
rel="noreferrer">examples I have seen online don't provide any real world
code, just vague examples.

Can
someone show me a real world use of a
closure?

Is this one, for
example?

var warnUser = function
            (msg) {
 var calledCount = 0;
 return function() {

            calledCount++;
 alert(msg + '\nYou have been warned ' + calledCount + '
            times.');
 };

};

var warnForTamper =
            warnUser('You can not tamper with our
            HTML.');
warnForTamper();
warnForTamper();

Answer

I've used closures to do things
like:

a = (function ()
            {

 var privatefunction = function () {

            alert('hello');
 }

 return {
 publicfunction :
            function () {
 privatefunction();
 }

            }
})();

As
you can see there, a is now an object, with a method
publicfunction ( a.publicfunction() )
which calls privatefunction, which only exists inside the
closure. You can NOT call
privatefunction directly (i.e.
a.privatefunction() ), just
publicfunction().

Its a
minimal example but maybe you can see uses to it? We used this to enforce public/private
methods.