JavaScript 创建对象和构造类实现代码_js面向对象

创建一个对象
Java代码

利用json（javaScript Object Notation）创建对象和上面同样的效果。
Java代码

function sayLoudly(){
alert(this.firstName.toUpperCase());
}
var newObject={
firstName:"frank",
sayName:function(){alert(this.firstName);},
sayLoudly:sayLoudly
};
//也可以这样
var newObject={
firstName:"frank",
sayName:function(){alert(this.firstName);},
sayLoudly:sayLoudly,
lastName:{
lastName:"ziggy",
sayName:function(){alert(this.lastName);}
}
};
newObject.lastName.sayName();

这样也ok
Java代码

function sayLoudly(){
alert(this.name.toUpperCase());
}
function sayName(){
alert(this.name);
}
var newObject={
name:"frank",
sayName:sayName,
sayLoudly:sayLoudly,
lastName:{
name:"ziggy",
sayName:sayName
}
};
newObject.lastName.sayName();

JavaScript 中的类，还有构造方法。。。
Java代码

function newClass(){
alert("constructor");
this.firstName="frank";
this.sayName=function(){alert(this.firstName);}
// return this;
}
//var nc=newClass();
var nc=new newClass();
//nc.firstName="ziggy"; is ok
nc.sayName();

还可以这样来构造类
Java代码

function newClass(){
this.firstName="frank";
}
newClass.prototype.sayName=function(){
alert(this.firstName);
}
var nc=new newClass();
nc.firstName="ziggy";
nc.sayName();
var nc2=new newClass();
nc2.sayName();

一般用prototypes来添加方法，这样不管有多少个实例，在内存中只有一个sayName方法。