javascript --- 面向对象 --- 封装

javascript中有原型对象和实例对象

如有疑问请参考：http://www.ruanyifeng.com/blog/2010/05/object-oriented_javascript_encapsulation.html

下面的代码可以用Rhino解释，代码如下：

/**
* Cat的对象
* name、color；猫科动物，吃老鼠
*/

print("--- --- --- 生成对象的原始模式 --- ---");
/*var Cat = {
    name : '',
    color : ''
};*/

var cat1 = {};
    cat1.name = "mao1";
    cat1.colr = "orange";

print("cat1 : name=" + cat1.name + ", color=" + cat1.colr);

print();
print("--- --- --- 原始模式的改进 --- ---");

function Cat1(name,color){
    return {
        name:name,
        color:color
    };
};

var cat2 = Cat1("mao2", "yellow");
print("cat2 : name=" + cat2.name + ", color=" + cat2.color);

print();
print("--- --- --- 构造函数模式 --- ---");

function Cat2(name, color){
    this.name = name;
    this.color = color;
}

var cat3 = new Cat2("mao3", "blue");
print("cat3 : name=" + cat3.name + ", color=" + cat3.color);
print("cat3.constructor == Cat2 --- " + (cat3.constructor == Cat2));
print("cat3 instanceof Cat2 --- --- " + (cat3 instanceof Cat2));

print();
print("--- --- --- 构造函数模式的问题 --- ---");

function Cat3(name, color){
    this.name = name;
    this.color = color;
    this.type = "猫科动物";
    this.eat = function(){
        print("吃老鼠");
    };
}

var cat4 = new Cat3("mao4", "red");
var cat5 = new Cat3("mao5", "pink");
print("cat4 : name=" + cat4.name + ", color=" + cat4.color + ", type=" + cat4.type);
cat4.eat();
print("cat5 : name=" + cat5.name + ", color=" + cat5.color + ", type=" + cat5.type);
cat5.eat();

print("cat4.type == cat5.type --- --- " + (cat4.type == cat5.type));
print("cat4.eat == cat5.eat() --- --- " + (cat4.eat == cat5.eat));

print();
print("--- --- --- Prototype模式 --- ---");

function Cat4(name,color){
    this.name = name;
    this.color = color;
}
Cat4.prototype.type = "猫科动物";
Cat4.prototype.eat = function(){
    print("吃老鼠");
};

var cat6 = new Cat4("mao6", "green");
var cat7 = new Cat4("mao7", "gray");
print("cat6 : name=" + cat6.name + ", color=" + cat6.color + ", type=" + cat6.type);
cat6.eat();
print("cat7 : name=" + cat7.name + ", color=" + cat7.color + ", type=" + cat7.type);
cat7.eat();

print("cat6.type == cat7.type --- --- " + (cat6.type == cat7.type));
print("cat6.eat == cat7.eat --- --- - " + (cat6.eat == cat7.eat));

print();
print("--- --- --- Prototype模式的验证方法 --- ---");

print("Cat4.prototype.isPrototypeOf(cat6) --- " + Cat4.prototype.isPrototypeOf(cat6));
print("Cat4.prototype.isPrototypeOf(cat5) --- " + Cat4.prototype.isPrototypeOf(cat5));

print('cat6.hasOwnProperty("name") --- --- ' + cat6.hasOwnProperty("name"));
print('cat6.hasOwnProperty("type") --- --- ' + cat6.hasOwnProperty("type"));

print('"name" in cat7 --- ---' + ("name" in cat7));
print('"colr" in cat7 --- ---' + ("colr" in cat7));
for(var prop in cat7) {
    print("\tcat7["+prop+"] = " + cat7[prop]);
} 

打印结果如下：

--- --- --- 生成对象的原始模式 --- ---
cat1 : name=mao1, color=orange

--- --- --- 原始模式的改进 --- ---
cat2 : name=mao2, color=yellow

--- --- --- 构造函数模式 --- ---
cat3 : name=mao3, color=blue
cat3.constructor == Cat2 --- true
cat3 instanceof Cat2 --- --- true

--- --- --- 构造函数模式的问题 --- ---
cat4 : name=mao4, color=red, type=猫科动物
吃老鼠
cat5 : name=mao5, color=pink, type=猫科动物
吃老鼠
cat4.type == cat5.type --- --- true
cat4.eat == cat5.eat() --- --- false

--- --- --- Prototype模式 --- ---
cat6 : name=mao6, color=green, type=猫科动物
吃老鼠
cat7 : name=mao7, color=gray, type=猫科动物
吃老鼠
cat6.type == cat7.type --- --- true
cat6.eat == cat7.eat --- --- - true

--- --- --- Prototype模式的验证方法 --- ---
Cat4.prototype.isPrototypeOf(cat6) --- true
Cat4.prototype.isPrototypeOf(cat5) --- false
cat6.hasOwnProperty("name") --- --- true
cat6.hasOwnProperty("type") --- --- false
"name" in cat7 --- ---true
"colr" in cat7 --- ---false
    cat7[name] = mao7
    cat7[color] = gray
    cat7[type] = 猫科动物
    cat7[eat] =
function () {
    print("\u5403\u8001\u9f20");
}