Question

此问题与Using "Object.create" instead of "new"不重复。使用Object.create

时，有问题的主题并不专注于正确传递参数

我很好奇我将如何使用Object.create而不是new来初始化对象。到目前为止，这是我的代码：

function Human(eyes) {
    this.eyes = eyes || false;
}

Human.prototype.hasEyes = function() {
    return this.eyes;
}

function Male(name) {
    this.name = name || "No name";
}

Male.prototype = new Human(true); //passing true to the Human constructor

var Sethen = new Male("Sethen");

console.log(Sethen.hasEyes());

如上所示，Male.prototype = new Human(true);使用true创建一个新对象。运行hasEyes()函数时，会按预期记录为true。

所以，我的问题是..使用Object.create我将如何以与传递true参数相同的方式进行此操作？

Answer 1

您必须使用Object.call(this)调用构造函数，然后传递参数。

function Human(eyes, phrase) {
    this.eyes = eyes || false;
    this.phrase = phrase;
}

Human.prototype.hasEyes = function() {
    return this.eyes;
}

Human.prototype.sayPhrase = function() {
    return this.phrase;
}

function Male(name) {
    Human.call(this, true, "Something to say"); //notice the call and the arguments
    this.name = name || "No name";
}

Male.prototype = Object.create(Human.prototype);

var Sethen = new Male("Sethen");

console.log(Sethen.hasEyes());
console.log(Sethen.sayPhrase());

console.log(Object.getOwnPropertyNames(Sethen));

这是有效的，现在对象Male的属性为eyes和phrase

Answer 2

这给出了关于原型继承模型的一些线索。

const Human = {
    constructor: function (eyes) {
        this.eyes = eyes || false;
    },
    hasEyes: function () {
        return this.eyes;
    }
};

let Male = Object.create(Human);

Male.constructor = function (name) {
    this.name = name || "No name";
    return Human.constructor.call(this, "true");
};

let Sethen = Object.create(Male);
Sethen.constructor = function() {
    return Male.constructor.call(this, 'Sethen');
};

Sethen.constructor();

console.log(Sethen.hasEyes());
console.log(Object.getOwnPropertyNames(Sethen));

使用Object.create而不是new时传递参数

2 个答案: