Why does Typescript let you create an object without specifying required fields?

Question

typescript

Good afternoon!
I created a class, after which I created an instance of an object from this class through the constructor. The object was successfully created and output to the console, the file was compiled into .js, BUT: why didn't I get an error that "Type '{}' is missing the following properties from type 'Vehicle': isSpecial, brand, model, and 2 more. " ? Indeed, in the class description, these fields are not optional, but nevertheless, I was able to create an object without specifying them, there was no error. But when I create an object like this: "const toyota: Vehicle = {}", there is an error. Through the constructor - no. Why?

class Vehicle {
  isSpecial: boolean;
  wheels: number;
  brand: string;
  model: string;
  mileage: number;
  isUsed: boolean;
  constructor (wheels: number, mileage: number) {
    this.wheels = wheels;
    this.mileage = mileage;
  }
  drive(): void {
    this.mileage += 100;
  };
}

const toyota: Vehicle = new Vehicle(4, 200);



console.log(toyota);

Answer 1

This is by design to better support everything already written and established practices.
Use the "strictPropertyInitialization" flag