29-Interface_Descriminated_Union.ts

/*
 **   [interface] + [type:'']
 **   switch case
 **
 **
 */

interface Bird {
  type: 'bird';
  flyingSpeed: number;
}

interface Horse {
  type: 'horse';
  runingSpeed: number;
}

type Animal = Bird | Horse;

function moveAnimal(animal: Animal) {
  let speed: number;
  switch (animal.type) {
    case 'bird':
      speed = animal.flyingSpeed;
      break;
    case 'horse':
      speed = animal.runingSpeed;
      break;
  }
  console.log('Moving at speed:' + speed);
}

moveAnimal({ type: 'bird', flyingSpeed: 2000 });