gistfile1.txt

versi C#

class Animal  {
  speak(){}
}

class Bird : Animal {
  fly(){}
}

class Dog : Animal {
  bark() {}
}

var animal //instance bisa Bird atau Dog
var dog = animal as Dog
if(dog != null) dog.bark()

var bird = animal as Bird
if(bird != null) bird.fly()

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yen di type script

if(animal instanceof Bird) animal.fly()
if(animal instanceof Dog) animal.bark()