Javascript 寄生组合式继承

接触了好几种继承模式了，在前一篇文章，我们就说到了一些继承方法，本以为组合是最好的，结果没想到还有。

故事从原型式继承说起：

function object(o) {
    function F(){}
    F.prototype = o;
    return new F();
}

var person = {
    name: "Nicholas",
    friends: ["Shelby", "Court", "Van"]
};

var anotherPerson = object(person);
anotherPerson.name = "Greg";
anotherPerson.friends.push("Rob");

var yetAnotherPerson = object(person);
yetAnotherPerson.name = "Linda";
yetAnotherPerson.friends.push("Barbie");

console.log(person.friends);

原型式继承似乎略像prototype的情况，输出为[ 'Shelby', 'Court', 'Van', 'Rob', 'Barbie' ]

之后我们可以用自带的Object.create()来代替定义的函数。

寄生式继承也是运用了这一特点

function createAnother(original) {
    var clone = Object.create(original);
    clone.sayHi = function() {
        console.log("hi");
    };
    return clone;
}

var person = {
    name: "Nicholas",
    friends: ["Shelby", "Court", "Van"]
};

var anotherPerson = createAnother(person);
anotherPerson.sayHi();

不懂的是为什么在这里定义的sayHi就无法共享给person。

而寄生组合式继承目前似乎被称为最高效的方式（-_-其实我也没明白）

function inheritPrototype(subType, superType) {
    var prototype = Object.create(superType.prototype);
    prototype.constructor = subType;
    subType.prototype = prototype;
}

function SuperType(name) {
    this.name = name;
    this.color = ["red", "blue", "green"];
}

SuperType.prototype.sayName = function() {
    console.log(this.name);
};

function SubType(name, age) {
    SuperType.call(this, name);

    this.age = age;
}

inheritPrototype(SubType, SuperType);

SubType.prototype.sayAge = function() {
    console.log(this.age);
};