Access Modifiers

public, private, and protected are the three access modifiers used in class to control its access from the outside. By default, all members (properties, fields, methods, or functions) are publicly accessible from outside the class.

class Car {
  constructor(name) {
    this.name = name;
  }
  static hello(x) {
    return "Hello " + x.name;
  }
}
let myCar = new Car("Toyota");
console.log(Car.hello(myCar)); // Hello Toyota

private members can access only internally within the class and cannot be accessible from outside. Private should start with #.

class Car {
  constructor(name) {
    this.name = name;
  }
  static hello(x) {
    return "Hello " + x.name;
  }
  #present(carname) {
    return 'I have a ' + this.carname;
  }
}
let myCar = new Car("Toyota");
console.log(myCar.#present("Camry")); // Error
console.log(Car.hello(myCar)); // Hello Toyota

protected fields are accessible only from inside the class and those extending it. These are useful for the internal interface as the inheriting class also gains access to the parent class. Protected fields with _ .

class Car {
  constructor(brand) {
    this.carname = brand;
  }
  _present() {
    return 'I have a ' + this.carname;
  }
}

class Model extends Car {
  constructor(brand, mod) {
    super(brand);
    this.model = mod;
  }
  show() {
    return this._present() + ', it is a ' + this.model;
  }
}

let myCar = new Model("Toyota", "Camry");
console.log(myCar.show()) // I have a Toyota, it is a Camry