JavaScript 学习二 类的定义方式

/* var object = new Object(); var string = new String(); var date = new Date(); var array = new Array(); array.push(1); array.push(2); array.push(3); alert(array.length); function compare(num1, num2) { var temp1 = parseInt(num1); var temp2 = parseInt(num2); if(temp1 < temp2) { return -1; } else if(temp1 == temp2) { return 0; } else { return 1; } } var array = [1,3,21]; array.sort(function(num1, num2) { var temp1 = parseInt(num1); var temp2 = parseInt(num2); if(temp1 < temp2) { return -1; } else if(temp1 == temp2) { return 0; } else { return 1; } } ); alert(array); var object = new Object(); object.name = "zhangsan"; object.sayName = function(name) { this.name = name; alert(this.name); } object.sayName("lisi"); */ //工厂方式定义类 /* function get() { alert("username: " + this.username + "/npassword: " + this.password); } function createObject(username, password) { var object = new Object(); object.username = username; object.password = password; object.get = get; return object; } var o1 = createObject("hello", "world"); //var o2 = createObject(); o1.get(); */ //构造函数方式 function Person(username, password) { this.username = username; this.password = password; this.get = function() { alert("username: " + this.username + "/npassword: " + this.password); } } var person = new Person("zhangsan", "123456"); person.get(); /** //原型方式创建类：prototype function Person() { } Person.prototype.username = new Array(); Person.prototype.password = "123"; Person.prototype.get = function() { alert("username: " + this.username + "/npassword: " + this.password); } var person = new Person(); var person2 = new Person(); person.username.push("zhangsan"); person.get(); person2.get(); */ /** //混合的构造函数与原型方式 //属性采用构造函数方式定义，方法采用原型方式定义(推荐的定义类的方式) function Person() { this.username = new Array(); this.password = "123"; } Person.prototype.get = function() { alert("username: " + this.username + "/npassword: " + this.password); } var p = new Person(); var p2 = new Person(); p.username.push("zhangsan"); p.get(); p2.get(); */ //动态的原型方式 function Person() { this.username = "zhangsan"; this.password = "123"; if(typeof Person.flag == "undefined") { //alert("executed"); Person.prototype.get = function() { alert("username: " + this.username + "/npassword: " + this.password); } Person.flag = true; } } var person = new Person(); var person2 = new Person(); person.get();