Introduction to Java Programming Chapter 4 Revel Questions and Answers with Complete Solutions

Introduction to Java Programming Chapter 4 Revel Questions and Answers with Complete Solutions What is the purpose of a constructor in Java? A constructor initializes a new object of a class. How do you call a method from another method within the same class? By using the method name directly or using the **this** keyword. What happens if you do not define a constructor in a class? Java provides a default constructor automatically. What is the difference between an instance variable and a local variable? An instance variable belongs to an object and persists as long as the object exists, while a local variable exists only within a method and is destroyed once the method finishes execution. How do you create an object of a class in Java? By using the **new** keyword followed by the class constructor. 2 What does the **this** keyword represent in Java? It represents the current instance of the class. What happens when a method is declared as **static**? It belongs to the class rather than any instance of the class. What is the purpose of method overloading? It allows multiple methods to have the same name but different parameter lists. How can a method in a subclass override a method in its superclass? By defining a method with the same name, return type, and parameters as the method in the superclass. What keyword is used to call a constructor of the superclass? **super** What is an accessor method? 3 A method that returns the value of an instance variable. What is a mutator method? A method that modifies the value of an instance variable. What is the default value of an uninitialized reference variable? **null** How do you prevent a method from being overridden? By declaring it as **final**. What happens when an object is no longer referenced? It becomes eligible for garbage collection.