Different forms of polymorphism

1. Ad-hoc Polymorphism

 Function or operator overloading based on different types

int add(int a, int b) {
  return a + b;
}

double add(double a, double b) {
  return a + b;
}

2. Parametric Polymorphism

Generic functions or types that can operate on any type.

identity :: a -> a
identity x = x

3. Subtype Polymorphism (or Inclusion Polymorphism)

Using a subclass where a superclass is expected, common in OOP.

class Animal {
  void makeSound() { }
}

class Dog extends Animal {
  void makeSound() { System.out.println("Bark"); }
}

class Cat extends Animal {
  void makeSound() { System.out.println("Meow"); }
}

public void playSound(Animal animal) {
  animal.makeSound();
}

4. Coercion Polymorphism

let result = 5 + " apples"; // result is "5 apples"

this form allows for automatic conversion of types in expressions. It often occurs in languages with implicit type conversion.