TypeScript 2.x By Example

Abstract class

An abstract class is a special type of class, which does not need to have an implementation of all the methods it defines. The primary use of an abstract class is to have a base class that defines all the common behaviors and lets the child classes manage the differences. This concept is very useful in writing large-scale object-oriented applications, where we want to define the behavior of a parent entity. 

The following example shows how to define an abstract class and abstract methods:

abstract class Book {  constructor(public author:string, public title:string,     public length: number){  }  abstract getFullTitle(): string ;}

To define a class as abstract, we just need to prefix the class name with the abstract keyword; the ...