一.使用构造函数创建对象
1.使用系统构造函数创建对象
举例:
1 var obj = new Object();2 obj.name = "小明";3 obj.age = 28;4 obj.eat = function(){5 console.log("小明喜欢吃西瓜");6 };7 console.log(obj.name);8 console.log(obj.age);9 obj.eat();
2.使用自定义构造函数创建对象
a.使用不带参数的自定义构造函数创建对象
举例:
1 function Person(){ 2 ????this.name = "小红"; 3 ????this.age = 28; 4 ????this.eat = function(){ 5 ????console.log("小红喜欢吃西瓜"); 6 } 7 var obj = new Person(); 8 console.log(obj.name); 9 console.log(obj.age);10 obj.eat();
b.使用带参数的自定义构造函数创建对象
举例:
function Person(name,age){ ???this.name = name; ???his.age = age; ???this.eat = function(){ ???????????console.log(this.name + "今年" + this.age + "岁了,喜欢吃西瓜"); ???????};}var obj = new Person("小光",18);var obj2 = new Person("小青",22);console.log(obj.name);console.log(obj.age);obj.eat();console.log(obj2.name);console.log(obj2.age);bj2.eat();c.定义构造函数时应遵循的命名规范
定义构造函数时函数名的首字母要大写
d.使用instanceof关键字来查看对象的类型
举例:
function Person(name,age){ ???this.name = name; ???this.age = age; ???this.eat = function(){ ???????????console.log(this.name + "今年" + this.age + "岁了,喜欢吃西瓜"); ???????};}function Dog(){ ???this.eat = function(){ ???????????onsole.log("狗喜欢吃骨头"); ???};}var obj = new Person("小光",18);var obj3 = new Dog();console.log(obj instanceof Person);console.log(obj instanceof Dog);console.log(obj3 instanceof Dog);二.工厂模式创建对象
举例:
???????<script> ???????????//使用工厂模式创建对象 ???????????function createObj(name,age,sex){ ???????????????var obj = new Object(); ???????????????obj.name = name; ???????????????obj.age = age; ???????????????obj.sex = sex; ???????????????obj.say = function(){ ???????????????????console.log("我是" + "this.sex" + "的"); ???????????????}; ???????????????return obj; ???????????} ???????????var obj = createObj("小黄",56,"男"); ???????????var obj = createObj("小紫",52,"男"); ???????????????????</script>说明:使用工厂模式创建对象其实就是讲创建对象的过程用函数封装起来,用于方便快捷的创建多个类似的对象,同时也存在问题,使用工厂模式创建的对象,无法判断哪个实例属于哪个对象,即使用instanceof关键字无意义
js创建对象的几种方式
原文地址：https://www.cnblogs.com/alan-1996/p/10459921.html