How to Override Methods in Java

Method Overriding in Java

Understanding Method Overriding in Java

In Java, method overriding is a powerful mechanism that allows a subclass to provide a specific implementation of a method that is already defined in its superclass. This enables polymorphic behavior, where a method call on a superclass reference can execute different behaviors based on the actual instance of the subclass.

Basic Concept:

When a subclass defines a method with the same signature (name, parameters, and return type) as a method in its superclass, it is said to override the superclass method. The overridden method in the subclass replaces the implementation of the superclass method during runtime polymorphism.

Rules for Method Overriding:

1) Method Signature:

The overriding method must have the same method signature as the method it is overriding in the superclass, including the method name, parameters, and return type.

2) Access Modifier:

The access modifier of the overriding method in the subclass must be the same as or less restrictive than the access modifier of the overridden method in the superclass. For example, if the superclass method is declared as public, the overriding method can be declared as public or protected, but not private.

3)Exception Handling:

The overriding method is allowed to throw any unchecked (runtime) exceptions or their subclasses. However, it cannot throw checked exceptions that are broader or new exceptions that are not present in the overridden method's throws clause.

Conclusion:

Method overriding in Java is a fundamental concept for achieving runtime polymorphism and building flexible and maintainable object-oriented systems. It allows subclasses to provide specialized behavior while adhering to the inheritance hierarchy defined by their superclasses. Understanding the rules and principles of method overriding is crucial for writing robust and extensible Java programs.