40 lines
916 B
Markdown
40 lines
916 B
Markdown
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---
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title: Add Methods After Inheritance
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localeTitle: 继承后添加方法
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---
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## 继承后添加方法
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### 方法
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就像下面的例子一样，必须创建一个对象的新实例 - `Dog` - 并且必须设置`prototype` 。
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```javascript
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function Bird() { }
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Bird.prototype = Object.create(Animal.prototype);
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Bird.prototype.constructor = Bird;
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```
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然后必须在Dog原型中添加一个新函数 - `bark()` - 。
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### 解
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```javascript
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function Animal() { }
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Animal.prototype.eat = function() { console.log("nom nom nom"); };
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function Dog() { }
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// Add your code below this line
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Dog.prototype = Object.create(Animal.prototype);
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Dog.prototype.constructor = Dog;
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Dog.prototype.bark = function() {
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console.log("Woof woof!");
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};
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// Add your code above this line
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let beagle = new Dog();
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beagle.eat(); // Should print "nom nom nom"
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beagle.bark(); // Should print "Woof!"
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```
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