JS組合繼承的通用工具函數

此工具函數沒實際意義，只是鑒於EXT的extend方法不太好理解，寫了一個簡化的extend方法，協助理解.

/** *  */E = {};E.extend = function(sub, sup) {//借用建構函式sub.prototype = sup;//保留父類的建構函式,以便在子類建構函式中用調用，將父類變數綁定在this下sub.prototype.superclass = sup.constructor;//因為重寫了建構函式所以重新指定constructor,以使instanceof表現正常sub.prototype.constructor = sub;//因為已經將變數綁定到子類上，所以刪除原型上被覆蓋的變數for (var i in sup) {if (typeof sup[i] !== 'function') {delete sup[i];}}return sub;};E.InterfaceFactory = {};E.InterfaceFactory.createInterface = function(methods) {var Interface = function() {};var f = typeof arguments[0] === 'string';var p = f ? arguments : arguments[0];var len = p.length;var _proto = Interface.prototype = {};for (var i = 0; i < len; i++) {_proto.p[i] = function() {throw new Error('no implements function');};}return new Interface();};

Test

var Person = function(name) {this.name = name;}Person.prototype.say = function () {alert('I am ' + this.name);}var SS = function(name, age) {this.superclass.call(this,name);this.age = age;}SS = E.extend(SS, new Person('sz'));var s = new SS('xx', 11);s.say();