Can you explain the principle of dynamic method dispatch in object-oriented languages?

Dynamic method dispatch is a mechanism where the choice of which method implementation to invoke occurs at runtime, not at compile time. In object-oriented languages like Java, this allows calling overridden methods of subclasses through references to the base class.

Example:

class Animal {
    void sound() {
        System.out.println("Some sound");
    }
}

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

public class Main {
    public static void main(String[] args) {
        Animal a = new Dog();
        a.sound(); // Will output "Bark" thanks to dynamic dispatch
    }
}

Here, the sound() method is called on an object of type Dog, even though the variable a is of type Animal. The decision of which method to invoke is made at runtime, ensuring polymorphism and code flexibility.