jQuery源码分析之Callbacks详解

                            list.splice(index, 1);
                            if (firing) {
                                //保证上面fire中正在执行的函数列表能够正确运行，fire中设定全局这些变量为的就是这里可以异步移除
                                if (index <= firingLength)//修正长度
                                    firingLength–;
                                if (index <= firingLength)//修正索引
                                    firingIndex–;
                            }
                        }
                    });
                }
                return this;
            },
            has: function (fn) {//是否包含一个回调函数
                return fn ? inArray(fn, list) > -1 : list && list.length;
            },
            empty: function () {//清空这个callbacks对象
                list = [];
                firingLength = 0;