Question

我正在尝试在JavaScript中模拟“类”语法。重新定义对象时，如何从对象的原型中调用该函数？在示例中，我尝试扩展Bear对象的声音功能。

function Animal(name) {
    this.name = name;
}
Animal.prototype.sound = function() { console.log("I'm " + this.name); }

function Bear(name) {
    Animal.call(this, name)
}
Bear.prototype = new Animal();
Bear.prototype.sound = function() { this.prototype.sound(); console.log("growl!"); }

const cal = new Bear("Callisto")
cal.sound() // Should be: I'm Callisto growl!
console.log(cal)

Answer 1

您可以直接在Animals原型上访问该方法：

Bear.prototype.sound = function() { 
 Animal.prototype.sound.call(this); 
 console.log("growl!"); 
};

重新定义原型方法

1 个答案: