function Observer() { this.fns = []; } Observer.prototype = { subscribe: function (fn) { this.fns.push(fn); }, unsubscribe: function (fn) { this.fns = this.fns.filter( function (el) { if (el !== fn) { return el; } } ); }, update: function (o, thisObj) { var scope = thisObj || window; this.fns.forEach( function (el) { el.call(scope, o); } ); } }; //测试 var o = new Observer; var f1 = function (data) { console.log('Robbin: ' + data + ', 赶紧干活了!'); }; var f2 = function (data) { console.log('Randall: ' + data + ', 找他加点工资去!'); }; o.subscribe(f1); o.subscribe(f2); o.update("Tom回来了!") //退订f1 o.unsubscribe(f1); //再来验证 o.update("Tom回来了!");