编写一个简单的 jQuery 插件（模板）

//You need an anonymous function to wrap around your function to avoid conflict
(function($){

    //Attach this new method to jQuery
    $.fn.extend({

        //This is where you write your plugin's name
        pluginname: function() {

            //options
            var defaults = {
                option1: "default_value"
            }

            var options = $.extend(defaults, options);

            //a public method
            this.methodName: function () {
                //call this method via $.pluginname().methodName();
            }

            //Iterate over the current set of matched elements
            return this.each(function() {

                var o = options;

                //code to be inserted here

            });
        }
    });

//pass jQuery to the function,
//So that we will able to use any valid Javascript variable name
//to replace "$" SIGN. But, we'll stick to $ (I like dollar sign: ) )      
})(jQuery);