up
This commit is contained in:
parent
83b93e5992
commit
9ad9063d00
742 changed files with 884 additions and 779 deletions
|
@ -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`.
|
Loading…
Add table
Add a link
Reference in a new issue