Extending: <https://stackoverflow.com/a/31047/235633>

Is there a way I can extend this custom jQuery function to use a callback? Essentially I want to be able to have a list of selectors and detect their existence and if they exist, I need to show them.

Instead of writing a thousand if statements, I rather write one function that uses a callback and 'this'.

The guy wrote:

```
jQuery.fn.exists = function(){return this.length>0;}

if ($(selector).exists()) {
    // Do something
}

```

But I need:

```
$('.selector1, .selector2, .selector3').exists(function({
    $(this).show();
});

```