javascript中定义私有方法(private method)

var Person = function(name,sex){
	this.name = name;
	this.sex = sex;		
	var _privateVariable = "";//私有变量	
	//构造器中定义的方法，即为私有方法
	function privateMethod(){	
		_privateVariable = "private value";
		alert("私有方法被调用！私有成员值：" + _privateVariable);				
	}
	privateMethod(); //构造器内部可以调用私有方法			
}

Person.prototype.sayHello = function(){
	alert("姓名：" + this.name + "，性别：" + this.sex);
}

var p = new Person("菩提树下的杨过","男");		
p.sayHello();

//p.privateMethod();//这里将报错，私成方法无法被实例调用
alert(p._privateVariable);//显示: undefined

var Person = function(){	
	var salary = 0.0;

	this.setSalary = function(value){
		salary = value;
	}

	this.getSalary = function(){
		return salary;
	}
}

var p = new Person();

p.setSalary(1000);
alert(p.getSalary());//返回1000
alert(p.salary);//返回undefined