Java Programming

Java MCQ: Which of the following is used to define a block of code that can handle exceptions in Java? a) try block b) catch block c) finally block d) All of the above Answer: d) All of the above Explanation: In Java, exception handling involves several constructs, including the try, catch, and finally blocks. […]

Java MCQ: Which of the following is a checked exception in Java? a) NullPointerException b) IOException c) ArithmeticException d) ArrayIndexOutOfBoundsException Answer: b) IOException Explanation: In Java, exceptions are categorized into two main types: checked exceptions and unchecked exceptions. Checked exceptions are exceptions that must be either caught or declared in the method signature using the

Java MCQ: Which of the following is a marker interface in Java? a) Serializable b) Runnable c) Cloneable d) Both a and c Answer: d) Both a and c Explanation: In Java, a marker interface is an interface that does not contain any methods or fields. Its purpose is to provide metadata to the Java

Java MCQ: What does the ‘super’ keyword do in Java? a) It refers to the superclass b) It creates a new object c) It overrides a method d) It finalizes an object Answer: a) It refers to the superclass Explanation: In Java, the super keyword is used to refer to the superclass (parent class) of

Java MCQ: What is the result of 10 + 20 + “30” in Java? a) 1030 b) 30 c) 102030 d) 3030 Answer: d) 3030 Explanation: In Java, the expression 10 + 20 + "30" results in "3030". This is because Java evaluates the expression from left to right. Initially, it adds 10 and 20,

Java MCQ: Which of the following loops is guaranteed to execute at least once? a) for loop b) while loop c) do-while loop d) None of the above Answer: c) do-while loop Explanation: The do-while loop in Java is a type of loop that is guaranteed to execute at least once, regardless of whether the

Java MCQ: Which keyword is used to create a constant variable in Java? a) final b) const c) static d) constant Answer: a) final Explanation: In Java, the final keyword is used to create a constant variable, meaning that the variable’s value cannot be changed once it has been assigned. This makes the variable immutable,

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: What is the correct syntax to declare a main method in Java? a) public static int main(String[] args) b) public static void main(String[] args) c) public void main(String[] args) d) static void main(String[] args) Answer: b) public static void main(String[] args) Explanation: The main method in Java is the entry point of any

Java MCQ: Which of the following statements is true about Java packages? a) A package is a way to organize classes in Java b) Packages are used to prevent naming conflicts c) Packages can be nested inside other packages d) All of the above Answer: d) All of the above Explanation: Java packages serve as

Java MCQ: Which of the following is the correct way to declare a variable in Java? a) int 1x = 10; b) int x = 10; c) float x = 1.0; d) string x = “Hello”; Answer: b) int x = 10; Explanation: In Java, variable declaration follows specific syntax rules. The correct way to

Java MCQ: Which method is used to compare two strings in Java for equality? a) equals() b) compare() c) compareTo() d) == Answer: a) equals() Explanation: In Java, the equals() method is used to compare two strings for equality. This method compares the content of the strings, character by character, and returns true if the

Java MCQ: What is the default value of a local variable in Java? a) 0 b) null c) undefined d) Local variables do not have a default value Answer: d) Local variables do not have a default value Explanation: In Java, local variables are those declared within a method, constructor, or block, and they are

Java MCQ: What is the default value of a boolean variable in Java? a) true b) false c) 0 d) null Answer: b) false Explanation: In Java, when a boolean variable is declared as an instance variable (a member of a class) and is not explicitly initialized, it is automatically assigned a default value. For

Java MCQ: Which keyword is used to inherit a class in Java? a) implement b) extends c) inherits d) derived Answer: b) extends Explanation: The keyword extends in Java is used to inherit a class, meaning that it allows one class to take on the properties and methods of another. This is a key feature

Java MCQ: Which method must be implemented by all threads in Java? a) run() b) start() c) execute() d) stop() Answer: a) run() Explanation: In Java, the run() method is the entry point for executing code in a thread. Every thread in Java is associated with an instance of a class that implements the Runnable

Java MCQ: Which operator is used to concatenate two strings in Java? a) + b) & c) && d) | Answer: a) + Explanation: In Java, the + operator is used to concatenate (join together) two strings. When this operator is used between two strings, it creates a new string that is the combination of

Java MCQ: Which of the following is not a primitive data type in Java? a) int b) boolean c) String d) char Answer: c) String Explanation: In Java, primitive data types are the basic types that are not objects and hold their values directly in memory. Java has eight primitive data types: byte, short, int,

Java MCQ: What is the size of an int variable in Java? a) 8 bits b) 16 bits c) 32 bits d) 64 bits Answer: c) 32 bits Explanation: In Java, the int data type is a 32-bit signed integer. This means it has a fixed size of 32 bits, which is equivalent to 4

1. What is the primary purpose of wrapper classes in Java? a) To provide a way to use primitive types as objects b) To wrap text data c) To encapsulate complex data structures d) To improve performance of collections Click to View Answer and Explanation Answer: a) To provide a way to use primitive types

1. What is a module in Java? a) A function or method b) A package of classes and interfaces c) A framework for dependency management d) A self-contained unit of code and data Click to View Answer and Explanation Answer: d) A self-contained unit of code and data Explanation: In Java, a module is a

1. What are records in Java? a) Data structures to store key-value pairs b) A feature to log application data c) A special type of class that holds immutable data d) A new collection type Click to View Answer and Explanation Answer: c) A special type of class that holds immutable data Explanation: Records in

1. What is JShell in Java? a) A Java IDE b) A Java package manager c) An interactive Java REPL d) A Java compiler Click to View Answer and Explanation Answer: c) An interactive Java REPL Explanation: JShell stands for Java Shell and is an interactive Read-Evaluate-Print Loop (REPL) tool introduced in Java 9, which