Complete Java SE 8 Developer Bootcamp - Polymorphism: Part 2

The video tutorial explains Java's reference types, focusing on polymorphism and method overriding. It highlights the importance of dynamic method dispatching, where the runtime object determines the method execution. The tutorial also discusses the role of final methods in preventing method overriding, enhancing execution speed by avoiding dynamic lookup.

What is the primary reason a reference type can store an object of a descendant type?

• Because Java does not enforce type safety.

• Because Java allows any object to be stored in any reference type.

• Because descendant types inherit properties and methods from their parent types.

• Because reference types are more flexible than object types.

Why is polymorphism important in Java programming?

• It allows for the use of multiple inheritance.

• It allows for the creation of multiple classes with the same name.

• It enables objects to take on multiple forms, promoting flexibility and separation of concerns.

• It ensures that all methods are executed in the order they are defined.

What happens during dynamic method dispatching?

• The runtime system determines which method to execute based on the actual object type.

• The method is executed based on the alphabetical order of method names.

• The compiler determines which method to execute based on the reference type.

• The method is executed based on the order of method calls.

In the context of method overriding, what role does the 'super' keyword play?

• It prevents the method from being overridden.

• It automatically optimizes the method for faster execution.

• It allows access to private methods of the parent class.

• It calls the method from the parent class to avoid recursion.

How does declaring a method as 'final' affect its behavior?

• It makes the method private to the class.

• It prevents the method from being overridden, ensuring a fixed implementation.

• It allows the method to be accessed by any class.

• It allows the method to be overridden by subclasses.

What is the main advantage of using final methods in terms of performance?

• They allow for more flexible method signatures.

• They are automatically optimized by the Java compiler.

• They can be executed by multiple threads simultaneously.

• They are compiled faster because they are not subject to dynamic method dispatching.

Why might it be frustrating to work with reference variables in Java?

• Because they can only store primitive data types.

• Because they can only call methods available to their reference type, not the actual object type.

• Because they require explicit memory management.

• Because they cannot be used in polymorphic contexts.