Java Programming

Java MCQ: Which of the following is true about encapsulation in Java? a) Encapsulation allows internal implementation to be hidden from the user b) Encapsulation is achieved using access modifiers c) Encapsulation makes code more flexible and maintainable d) All of the above Answer: d) All of the above Explanation: Encapsulation in Java is the […]

Java MCQ: What does the ‘implements’ keyword do in Java? a) It is used to inherit a class b) It is used to implement an interface c) It is used to override a method d) It is used to define an abstract method Answer: b) It is used to implement an interface Explanation: The implements

Java MCQ: What is the purpose of the ‘this’ keyword in Java? a) To refer to the current class instance b) To refer to the superclass instance c) To call a method in the superclass d) To return an instance of the superclass Answer: a) To refer to the current class instance Explanation: In Java,

Java MCQ: Which of the following statements about Java constructors is true? a) Constructors must have a return type b) Constructors can be abstract c) Constructors cannot be synchronized d) Constructors do not have a return type Answer: d) Constructors do not have a return type Explanation: Constructors in Java are special methods used to

Java MCQ: Which of the following is true about the ‘final’ keyword in Java? a) The final keyword can be applied to classes, methods, and variables b) A final method cannot be overridden c) A final class cannot be subclassed d) All of the above Answer: d) All of the above Explanation: The final keyword

Java MCQ: Why is the ‘super’ keyword used in Java? a) To create a superclass b) To call a method in the current class c) To refer to the immediate parent class object d) To override a method in the superclass Answer: c) To refer to the immediate parent class object Explanation: The super keyword

Java MCQ: Which of the following is not a feature of Java? a) Dynamic b) Platform-independent c) Machine-dependent d) Multithreaded Answer: c) Machine-dependent Explanation: Java is designed to be platform-independent, meaning that Java programs can run on any device or operating system that has the Java Virtual Machine (JVM) installed. This “write once, run anywhere”

Java MCQ: Which of the following is not a valid access modifier in Java? a) private b) protected c) public d) internal Answer: d) internal Explanation: In Java, the valid access modifiers are private, protected, and public. These modifiers control the visibility of classes, methods, and variables. private makes a member accessible only within the

Java MCQ: Which of the following best describes method overloading in Java? a) Method overloading occurs when two methods in the same class have the same name but different parameter lists b) Method overloading is the process of overriding a method in a subclass c) Method overloading refers to the runtime resolution of method calls

Java MCQ: Which of the following is a characteristic of the ‘transient’ keyword in Java? a) It prevents serialization of the variable b) It ensures that the variable is serialized c) It allows the variable to be accessed from any thread d) It makes the variable immutable Answer: a) It prevents serialization of the variable

Java MCQ: Which of the following is used to handle exceptions in Java? a) if-else b) for loop c) switch-case d) try-catch Answer: d) try-catch Explanation: In Java, exceptions are handled using the try-catch block. When an exception occurs in the try block, the control is transferred to the catch block where the exception is

Java MCQ: Which of the following is true about the ‘static’ keyword in Java? a) Static methods belong to the class, not instances b) Static methods can access instance variables directly c) Static methods can be abstract d) Static methods can override instance methods Answer: a) Static methods belong to the class, not instances Explanation:

Java MCQ: Which of the following is a wrapper class in Java? a) int b) Integer c) float d) boolean Answer: b) Integer Explanation: In Java, a wrapper class is an object representation of a primitive data type. The Integer class is a wrapper class for the primitive data type int. Wrapper classes provide a

Java MCQ: Which of the following best describes polymorphism in Java? a) Polymorphism allows methods to have the same name but different parameter lists b) Polymorphism allows an object to take on many forms c) Polymorphism is implemented using the ‘extends’ keyword d) Both a and b Answer: d) Both a and b Explanation: Polymorphism

Java MCQ: Which of the following is true about inheritance in Java? a) Inheritance allows a class to inherit fields and methods from another class b) Java supports multiple inheritance through classes c) Inheritance is implemented using the ‘implements’ keyword d) Inheritance prevents method overriding Answer: a) Inheritance allows a class to inherit fields and

Java MCQ: Which of the following best describes encapsulation in Java? a) Encapsulation is the technique of bundling data and methods that operate on that data within a single unit b) Encapsulation is the process of inheriting methods from a superclass c) Encapsulation is the use of access modifiers to restrict access to data d)

Java MCQ: Which of the following is not a valid access modifier in Java? a) private b) protected c) public d) internal Answer: d) internal Explanation: In Java, the valid access modifiers are private, protected, and public. These modifiers control the visibility of classes, methods, and variables. private makes a member accessible only within the

Java MCQ: Which of the following is a characteristic of the ‘transient’ keyword in Java? a) It prevents serialization of the variable b) It ensures that the variable is serialized c) It allows the variable to be accessed from any thread d) It makes the variable immutable Answer: a) It prevents serialization of the variable

Java MCQ: Which of the following is true about the ‘super’ keyword in Java? a) ‘super’ is used to refer to the immediate parent class object b) ‘super’ can be used to call parent class methods c) ‘super’ can be used to call parent class constructors d) All of the above Answer: d) All of

Java MCQ: Which of the following statements is true about the ‘abstract’ keyword in Java? a) An abstract class cannot be instantiated b) Abstract methods do not have a body c) A class must be declared abstract if it contains abstract methods d) All of the above Answer: d) All of the above Explanation: The

Java MCQ: Which of the following is true about the ‘final’ keyword in Java? a) The final keyword can be applied to classes, methods, and variables b) A final method cannot be overridden c) A final class cannot be subclassed d) All of the above Answer: d) All of the above Explanation: The final keyword

Java MCQ: Which of the following is not an exception handling keyword in Java? a) try b) catch c) finally d) throw Answer: d) throw Explanation: In Java, the exception handling mechanism is built around the try, catch, and finally blocks. The try block contains the code that might throw an exception, and the catch

Java MCQ: Which of the following statements about interfaces in Java is true? a) An interface can have instance variables b) An interface can extend multiple interfaces c) An interface can implement another interface d) An interface can have a constructor Answer: b) An interface can extend multiple interfaces Explanation: In Java, an interface can

Java MCQ: Which of the following is the correct way to declare a constant in Java? a) const int MAX_VALUE = 100; b) final int MAX_VALUE = 100; c) static int MAX_VALUE = 100; d) abstract int MAX_VALUE = 100; Answer: b) final int MAX_VALUE = 100; Explanation: In Java, the correct way to declare

Java MCQ: Which of the following best describes method overloading in Java? a) Method overloading occurs when two methods in the same class have the same name but different parameter lists b) Method overloading is the process of overriding a method in a subclass c) Method overloading refers to the runtime resolution of method calls