接口及继承相关方法

类式继承：

function dw(x) {document.writeln(x + "<br />");<br /> }function extend(subClass, superClass) {var F = function(){};F.prototype = superClass.prototype;subClass.prototype = new F();subClass.prototype.constructor = subClass;//superClass属性用来弱化sub,super之间的耦合，可以使用此属性调用超类中的方法subClass.superClass = superClass.prototype;if (superClass.prototype.constructor == Object.prototype.constructor) {superClass.prototype.constructor = superClass;}}function Person(name) {this.name = name;<br /> }<br /> Person.prototype.getName = function(){return this.name;<br /> }function Author(name, books) {Author.superClass.constructor.call(this, name);//Person.call(this, name);　//这种方式也可，但将超类名称固化在声明中，增加了耦合this.books = books;<br /> }<br /> extend(Author, Person);<br /> Author.prototype.getBooks = function(){return this.books;<br /> }<br /> Author.prototype.getName = function(){var name = Author.superClass.getName.call(this);return name + ", Author of " + this.getBooks();<br /> }var a = new Author("tom", "DP");<br /> dw(a.getBooks());<br /> dw(a.getName());

 

 

 

//原型式继承<br /> function clone(object){function F(){};F.prototype = object;return new F;<br /> }<br /> //混元类<br /> function augment(receivingClass, givingClass){if(arguments[2]){for(var i=2; i<arguments.length; i++){receivingClass.prototype[arguments[i]] = givingClass.prototype[arguments[i]];}}else{for(methodName in givingClass.prototype){if(!receivingClass.prototype[methodName]){receivingClass.prototype[methodName] = givingClass.prototype[methodName];}}}<br /> }

 

接口：

var Interface = function(name, methods){if(arguments.length != 2){throw new Error("Interface constructor called with "+ arguments.length + "arguments,but expected exactly 2.");}this.name = name;this.methods = [];for(var i=0; i<methods.length; i++){if(typeof methods[i] !== "string"){throw new Error("interface need the method name as a string.");}this.methods.push(methods[i]);}<br /> }<br /> Interface.ensureImplements = function(object){if(arguments.length < 2){throw new Error("Function Interface.ensureImplements called with"+ arguments.length + " arguments,but expected at least 2.")}for(var i=1; i<arguments.length; i++){var interfaceElem = arguments[i];if(interfaceElem.constructor !== Interface){throw new Error("");}for(var j=0; j<interfaceElem.methods.length; j++){var method = interfaceElem.methods[j];if(!object[method] || typeof object[method] !== 'function'){throw new Error(method + " was not found")}}}<br /> }<br /> //test code<br /> var Com = new Interface("Com",['add','remove','save']);<br /> var createT = function(){//this.add = function(){};this.remove = function(){};//this.save = function(){};<br /> }<br /> var t1 = new createT();<br /> Interface.ensureImplements(t1,Com);

 

继承：