Understanding Method Overriding in Java: Why b.show() Doesn't Print "SuperClass"

Explore the concept of method overriding in Java and understand why calling `b.show()` in an inherited class might not print "SuperClass" from the base class.
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Understanding Method Overriding in Java: Why b.show() Doesn't Print "SuperClass"

Java is a versatile and powerful language, but it can sometimes be confusing to new programmers, especially when dealing with inheritance and method overriding. One common area of confusion is understanding why calling b.show() on an object of type B might not print "SuperClass" from the base class A. Let's demystify this concept.

Inheritance in Java

Java's object-oriented nature means you can create complex hierarchies of classes that build on each other. At the core of this is inheritance, where one class (the child or subclass) inherits characteristics (methods and fields) from another class (the parent or superclass). This allows for creating a more understandable and maintainable code structure.

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In the above example, class B inherits from class A and overrides the show method.

Method Overriding

Method overriding is essential in Java, allowing a subclass to provide a specific implementation of a method that is already defined in its superclass. It's a way to achieve polymorphism, a core concept in Java that allows a single action to behave differently based on the object that is invoking the action.

When you have:

[[See Video to Reveal this Text or Code Snippet]]

Here, b.show() calls the show method in the subclass B, not the superclass A. It's because of the behavior of method overriding. The show method in B replaces the show method in A. So, calling b.show() will output "SubClass" because that is what the show method in B defines.

Key Points

Inheritance allows one class to inherit properties and methods from another.

Method overriding lets a subclass provide a specific implementation of a method that is declared in its parent class.

When an overridden method is called on an instance of the subclass, the method defined in the subclass is executed, not the one in the superclass.

Why b.show() Doesn't Print "SuperClass"

Due to method overriding, when b.show() is invoked, Java calls the overridden method in the subclass B, thus printing "SubClass". The superclass method is replaced at runtime by the subclass's version. This is a fundamental part of Java's polymorphism and object-oriented features.

Understanding method overriding and its impact on inheritance is crucial for writing effective Java code and leveraging the full range of object-oriented programming principles. Make sure you are well-versed in these concepts to avoid any confusion and to build robust applications.