This commit is contained in:
Ilya Kantor 2017-03-21 17:14:05 +03:00
parent ab9ab64bd5
commit 97c8f22bbb
289 changed files with 195 additions and 172 deletions

View file

@ -1,46 +0,0 @@
Here's the line with the error:
```js
Rabbit.prototype = Animal.prototype;
```
Here `Rabbit.prototype` and `Animal.prototype` become the same object. So methods of both classes become mixed in that object.
As a result, `Rabbit.prototype.walk` overwrites `Animal.prototype.walk`, so all animals start to bounce:
```js run
function Animal(name) {
this.name = name;
}
Animal.prototype.walk = function() {
alert(this.name + ' walks');
};
function Rabbit(name) {
this.name = name;
}
*!*
Rabbit.prototype = Animal.prototype;
*/!*
Rabbit.prototype.walk = function() {
alert(this.name + " bounces!");
};
*!*
let animal = new Animal("pig");
animal.walk(); // pig bounces!
*/!*
```
The correct variant would be:
```js
Rabbit.prototype.__proto__ = Animal.prototype;
// or like this:
Rabbit.prototype = Object.create(Animal.prototype);
```
That makes prototypes separate, each of them stores methods of the corresponding class, but `Rabbit.prototype` inherits from `Animal.prototype`.