University of Central Florida (UCF) COP3330 Object Oriented Programming Final Practice Exam

Java achieves runtime polymorphism primarily through method overriding in subclasses. This concept allows a subclass to provide a specific implementation of a method that is already defined in its superclass. When a method is invoked on an object, the Java Virtual Machine (JVM) determines which version of the method to execute at runtime based on the actual object type rather than the reference type. This allows for dynamic method resolution, where the method that gets executed depends on the object's class.

For example, if a superclass has a method `display()` and a subclass overrides this method with its own implementation, when a reference of the superclass type points to the subclass instance and the `display()` method is called, the JVM will invoke the subclass's implementation. This allows for flexibility and enhances the capability of polymorphism in object-oriented programming, enabling different objects to be treated as instances of their base type while still utilizing their specific behaviors.

The other options do touch on important concepts in Java, but they do not directly relate to the mechanism of runtime polymorphism. Using the same method name in different classes could indicate method overloading, which is resolved at compile time, not runtime. Compiling methods into bytecode is part of Java's compilation process but does not relate to polymorphism.