jQuery链式调用

 <script>
          var arr = function(){
            return new arr.prototype.init();
        }
        arr.prototype.init = function(){//介质
            return this;
        }
        arr.prototype.ded1 = function(){
            console.log(1);
            return this;
        }
        arr.prototype.ded2 = function(){
            console.log(2);
            return this;
        }

        arr.prototype.init.prototype = arr.prototype;
        arr().ded1().ded2();
  </script>

arr.prototype.init.prototype = arr.prototype;关键步骤

(function(){
        var jQuery = function(){
            return new jQuery.fn.init();
        }

        jQuery.fn = jQuery.prototype = {
            constructor : jQuery,
            init : function(){
                return this;
            },
            say : function(){
                console.log('say:hello');
                return this;
            },
            tell : function(){
                console.log('tell:hello');
                return this;
            }
        }

        jQuery.fn.init.prototype = jQuery.prototype;

        jQuery().tell();
        jQuery().say();
        console.log( jQuery() );
        console.log( jQuery.fn );
        console.log( jQuery.prototype );
    })()