How to use a basic way to extend the abstract class with Generics In Typescript
In this approach, we will see the basic way to extend the abstract class with generics with 3 steps:
- Create a class with an abstract keyword and add a generic type parameter using angle brackets (<>).
- Use the generic type parameters in methods or properties within the abstract class.
- Extend the abstract class from other classes by providing types for the generic parameters.
Syntax:
abstract class Classname<Generic> {
Visibility Prop_Name: Generic = Initial_Value;
Method_Name(Parameter: Generic): Return_Type{ ... }
}
class NormalClass extends Abstract_Class<Generic_Type> { ... }
Example : The below example will create a simple abstract class SuperClass with a generic type parameter T. It has a method pushItem that accepts an item of type T and stores it in an array of type T[].
Javascript
abstract class SuperClass<T> { protected NumArray: T[] = []; pushNumber(num: T): void { this.NumArray.push(num); } abstract ShowNumbers(): void;}class SubClass extends SuperClass<number> { showNumbers(): void { console.log("Pushed Numbers are: ", this.NumArray.join(", ")); }}const numberSeries = new SubClass();numberSeries.pushNumber(1);numberSeries.pushNumber(2);numberSeries.showNumbers(); |
Output:
Pushed Numbers are: 1, 2
How to Extend abstract class with Generics in Typescript ?
In Typescript, an abstract class is the base class that is inherited by other classes without having to define its members. Generic is the feature with which you can create a variable that represents a type in classes, functions, and type aliases that don’t need to define the types that they use explicitly.
There are 3 approaches given below to extend an abstract class with generics:
Table of Content
- Using a basic way to extend the abstract class with Generics
- Extending with Generic Constraints
- With multiple type parameters in Generics