Add jQuery function to specific elements

Question

I know that you can add new jQuery functions by $.fn.someFunction = function()

However, I want to add functions to specific elements only. I tried this

Answer 1

yo can do the above with this:

$.fn.testFn = function(){
    this.each(function(){
        var className = $(this).attr('class');
        $(this).html(className);
    });    
};

$('li').testFn(); //or any element you want

Test: http://jsfiddle.net/DarkThrone/nUzJN/