Arik Chakma
abbeb717d1
* Add Javascript questions * wip: add more questions * wip: add ternary operator * wip: add more questions * wip: add more questions * wip: add more questions * wip: add more questions * fix: set example * wip: add more questions * wip: add more question * wip: add more questions * wip: add more questions * wip: add more questions * wip: add more questions * wip: add more questions * wip: add more questions * wip: add more questions * wip: add another question * wip: add more questions * wip: add more questions * wip: add more questions * wip: add more questions * wip: add more questions * wip: add more questions * wip: add more questions * wip: add more questions
39 lines
1.2 KiB
Markdown
39 lines
1.2 KiB
Markdown
Inheritance is a way to create a new `Class` from an existing `Class`. The new `Class` inherits all the properties and methods from the existing `Class`. The new `Class` is called the child `Class`, and the existing `Class` is called the parent `Class`.
|
|
|
|
## Example
|
|
|
|
```js
|
|
class Roadmap {
|
|
constructor(name, description, slug) {
|
|
this.name = name;
|
|
this.description = description;
|
|
this.slug = slug;
|
|
}
|
|
|
|
getRoadmapUrl() {
|
|
console.log(`https://roadmap.sh/${this.slug}`);
|
|
}
|
|
}
|
|
|
|
class JavaScript extends Roadmap {
|
|
constructor(name, description, slug) {
|
|
super(name, description, slug);
|
|
}
|
|
|
|
greet() {
|
|
console.log(`${this.name} - ${this.description}`);
|
|
}
|
|
}
|
|
|
|
const js = new JavaScript(
|
|
'JavaScript Roadmap',
|
|
'Learn JavaScript',
|
|
'javascript'
|
|
);
|
|
|
|
js.getRoadmapUrl(); // https://roadmap.sh/javascript
|
|
js.greet(); // JavaScript Roadmap - Learn JavaScript
|
|
```
|
|
|
|
In the above example, the `JavaScript` class inherits the `getRoadmapUrl()` method from the `Roadmap` class. This is because the `JavaScript` class extends the `Roadmap` class using the `extends` keyword. In the `JavaScript` class, the `getRoadmapUrl()` method is not found, so JavaScript looks up the prototype chain and finds the `getRoadmapUrl()` method in the `Roadmap` class.
|