readmcqs

Are you preparing for a Java certification or interview? Testing your knowledge with Java MCQ questions and answers is a great way to assess your understanding of core concepts. Below are some commonly asked multiple-choice questions along with explanations to help you strengthen your Java skills. 1. What is the output of the following code? java Copy public class Main { public static void main(String[] args) { System.out.println(10 + 20 + "Java"); } } Options: A) 30Java B) 1020Java C) Compilation Error D) Runtime Error Answer: A) 30Java Explanation: The + operator performs addition first (10 + 20 = 30) and then concatenates with "Java". 2. Which keyword is used to prevent method overriding in Java? Options: A) static B) final C) abstract D) private Answer: B) final Explanation: The final keyword prevents a method from being overridden in subclasses. 3. What does JVM stand for? Options: A) Java Virtual Machine B) Java Variable Method C) JRE Virtual Memory D) Just Virtual Machine Answer: A) Java Virtual Machine Explanation: JVM is the runtime engine that executes Java bytecode. 4. Which collection class is synchronized by default? Options: A) ArrayList B) HashSet C) Vector D) LinkedList Answer: C) Vector Explanation: Vector is thread-safe and synchronized, unlike other collections. 5. What is the default value of a boolean in Java? Options: A) true B) false C) null D) 0 Answer: B) false Explanation: Uninitialized boolean variables default to false. Practicing Java MCQ questions and answers helps reinforce key concepts. Have more questions or need clarification? Drop them in the comments below!