Abstract classes

An abstract class cannot be instantiated and acts as a base template for subclasses. Use it to share common logic and enforce required methods.

Example

abstract class Shape {
  abstract getArea(): number;
  printArea() {
    console.log("Area:", this.getArea());
  }
}
class Circle extends Shape {
  constructor(private radius: number) {
    super();
  }
  getArea() {
    return Math.PI * this.radius ** 2;
  }
}
const circle = new Circle(10);
circle.printArea();

Notes

• abstract methods have no implementation and must be overridden.
• new Shape() is not allowed.
• Useful for class hierarchies with shared behavior.