Old-style Inheritance

index.ts

declare class Vehicle {
    engines: number;
    ignition(): void;
    drive(): void;
}

declare class Car extends Vehicle {
    wheels: number;
}

// "Traditional JS Class" `Vehicle`
function Vehicle(this: Vehicle) {
	this.engines = 1;
}
Vehicle.prototype.ignition = function() {
	console.log( "Turning on my engine." );
};
Vehicle.prototype.drive = function() {
	this.ignition();
	console.log( "Steering and moving forward!" );
};

// Natural inheritance??
function Car(this: Car) {
    // More or less equivalent to super()
    Vehicle.call(this);

	// now, let's modify our `car` to specialize it
	this.wheels = 4;

	// override `Vehicle::drive()`
	this.drive = function() {
		Vehicle.prototype.drive.call( this );
		console.log( "Rolling on all " + this.wheels + " wheels!" );
	};
}
Car.prototype = Vehicle.prototype as Car;

var myCar = new Car();

myCar.drive();
// Turning on my engine.
// Steering and moving forward!
// Rolling on all 4 wheels!

declare class Vehicle {
    engines: number;
    ignition(): void;
    drive(): void;
}

declare class Car extends Vehicle {
    wheels: number;
}

// "Traditional JS Class" `Vehicle`
function Vehicle(this: Vehicle) {
	this.engines = 1;
}
Vehicle.prototype.ignition = function() {
	console.log( "Turning on my engine." );
};
Vehicle.prototype.drive = function() {
	this.ignition();
	console.log( "Steering and moving forward!" );
};

// Natural inheritance??
function Car(this: Car) {
  // More or less equivalent to super()
  Vehicle.call(this);

	// now, let's modify our `car` to specialize it
	this.wheels = 4;
}

Car.prototype.drive = function() {
	Vehicle.prototype.drive.call( this );
	console.log( "Rolling on all " + this.wheels + " wheels!" );
};
Object.setPrototypeOf(Car.prototype, Vehicle.prototype as Car);

var myCar = new Car();

myCar.drive();
// Turning on my engine.
// Steering and moving forward!
// Rolling on all 4 wheels!