Classes And Functions in Ts. Classes: • Ts add helps to add type annotations for the classes.

class User {
  constructor(public name: string, public age: number) {}
}
const ue = new User("github", 24); 

• In Ts we don't need to initialize the properties and values inside the constructor if we are using access modifiers in the params. TypeScript will automatically initialise and assign values to class properties. Getters / Setters: • Classes can also have accessors • For the getter function we can able to set return value type but for setter function we can't. • setter functions are always expected props. • If a getter exists but no setter the property is automatically readonly • If the type of the setter parameter is not specified, it is inferred from the return type of the getter • For class props always try to use _ name convention for better maintainbility.

class User {
  private _currentCount: number = 0;
  constructor(public name: string, public age: number) {}

  get fetch_name(): string {
    return this._name;
  }

  get fetchCount(): number {
    return this._currentCount;
  }

  set increaseCount(prop: number) {
    this._currentCount = prop + this._currentCount;
    this.logData();
  }

  private logData(): void {
    console.log("Count Increased");
  }
}

const fetchUser = new User("github", 24);

Abstract: • If classes or method are marked as abstract those are only for readonly purposes, means they can be only used as base class/sub class. • So that reason we can't create object on the class who are marked as abstract.

abstract class Photo {
  constructor(public isCameraOn: boolean, public isFlashOn: boolean) {}
}

class Phone extends Photo {}
const ph = new Phone(true, true);

#typescript #javascript