Polymorphism in Java: A Simplified Explanation

Introduction to Polymorphism

Polymorphism is a fundamental concept in object-oriented programming that allows objects of different classes to be treated as objects of a common superclass. It promotes flexibility, extensibility, and code reusability in Java.

Polymorphism with Inheritance

Polymorphism is closely associated with inheritance. It allows objects of derived classes to be treated as objects of the base class. This means you can create a collection of objects that share a common base class and access their unique behaviors through a common interface.

class Shape {
    void draw() {
        System.out.println("Drawing a shape");
    }
}
class Circle extends Shape {
    @Override
    void draw() {
        System.out.println("Drawing a circle");
    }
}
class Rectangle extends Shape {
    @Override
    void draw() {
        System.out.println("Drawing a rectangle");
    }
}
    

Polymorphic Behavior

To achieve polymorphic behavior, you create an array, list, or collection of objects of the base class. You can then call the specific methods of the derived classes without knowing their exact type at compile time.

Shape[] shapes = new Shape[2];
shapes[0] = new Circle();
shapes[1] = new Rectangle();
for (Shape shape : shapes) {
    shape.draw();
}
    

Dynamic Method Binding

Polymorphism relies on dynamic method binding. When you call a method on an object, Java determines at runtime which version of the method (from the base class or derived class) should be executed. This allows for flexibility and runtime decision-making.

Conclusion

Polymorphism simplifies the handling of objects in Java by allowing you to work with a common interface while benefiting from the unique behaviors of derived classes. You've learned the basic principles of polymorphism with inheritance in this guide. As you continue your journey in Java programming, you'll appreciate the power and flexibility that polymorphism offers.