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Java MCQ: Which of the following is true about the ExecutorService in Java? a) It allows for direct management of threads b) It is used for managing a pool of threads c) It cannot return results from submitted tasks d) It is a subclass of the Thread class Answer: b) It is used for managing […]

Java MCQ: What is the purpose of the wait() method in Java? a) To pause the execution of a thread indefinitely b) To release the lock held by a thread and wait until another thread notifies it c) To start a new thread d) To terminate a thread Answer: b) To release the lock held

Java MCQ: Which of the following mechanisms is used to achieve thread synchronization in Java? a) Semaphore b) Synchronized block c) Deadlock d) Thread pool Answer: b) Synchronized block Explanation: The synchronized block in Java is used to achieve thread synchronization. Synchronization is the mechanism that ensures that only one thread can access a resource

Java MCQ: Which of the following best describes the lifecycle of a Java thread? a) New, Runnable, Running, Blocked, Dead b) New, Ready, Executing, Blocked, Terminated c) New, Runnable, Blocked, Waiting, Terminated d) New, Runnable, Running, Waiting, Terminated Answer: d) New, Runnable, Running, Waiting, Terminated Explanation: The lifecycle of a Java thread consists of the

Java MCQ: Which method must be overridden when implementing the Runnable interface? a) start() b) run() c) execute() d) call() Answer: b) run() Explanation: When implementing the Runnable interface in Java, you must override the run() method. The run() method contains the code that defines the task to be executed by the thread. The Runnable

Java MCQ: What is the primary purpose of the Thread class in Java? a) To execute SQL queries b) To represent and control threads of execution in a program c) To manage file I/O operations d) To create graphical user interfaces Answer: b) To represent and control threads of execution in a program Explanation: The

Java MCQ: Can the Builder Pattern be used with Java Records? a) No, Java Records do not support the Builder Pattern b) Yes, but only through a third-party library c) Yes, by manually implementing a Builder class d) Yes, by using a built-in Java Builder API Answer: c) Yes, by manually implementing a Builder class

Java MCQ: Can you customize the default behavior of the canonical constructor in Java Records? a) No, the canonical constructor cannot be customized b) Yes, by defining a compact constructor c) Yes, by overriding the constructor method d) Yes, but only for records with a single field Answer: b) Yes, by defining a compact constructor

Java MCQ: How do you access the fields of a Java Record? a) Using getter methods like getName() and getAge() b) Using field names directly like name and age c) Using generated methods with the same name as the fields like name() and age() d) Using reflection only Answer: c) Using generated methods with the

Java MCQ: Which of the following best describes the difference between Java Records and Lombok? a) Lombok generates boilerplate code using annotations, while records are a built-in language feature b) Lombok is used only for testing, while records are used in production code c) Lombok is part of the Java standard library, while records are

Java MCQ: How can Java Records be used with Spring Boot applications? a) As a replacement for all Spring Beans b) To define immutable data transfer objects (DTOs) c) To replace all Spring Controllers d) As a substitute for the application.properties file Answer: b) To define immutable data transfer objects (DTOs) Explanation: Java Records can

Java MCQ: Which of the following is true about the constructors in Java Records? a) Records cannot have custom constructors b) Records can only have parameterless constructors c) Records can have custom constructors that validate input or compute derived fields d) Records must have at least two constructors Answer: c) Records can have custom constructors

Java MCQ: What is the output of the following code snippet involving a Java Record? public record Point(int x, int y) {} public class Main { public static void main(String[] args) { Point p1 = new Point(1, 2); Point p2 = new Point(1, 2); System.out.println(p1.equals(p2)); } } a) true b) false c) Compilation error d)

Java MCQ: How do records differ from traditional classes in Java? a) Records are mutable by default, while classes are immutable by default b) Records automatically generate methods like equals(), hashCode(), and toString() c) Records cannot implement interfaces d) Records support inheritance, while classes do not Answer: b) Records automatically generate methods like equals(), hashCode(),

Java MCQ: What is the primary purpose of Java Records? a) To create mutable data structures b) To simplify the creation of immutable data classes c) To enhance performance d) To replace all existing classes Answer: b) To simplify the creation of immutable data classes Explanation: The primary purpose of Java Records is to simplify

Java MCQ: Which method is used to obtain the superclass of a class using Java Reflection? a) getSuperclass() b) getParentClass() c) getBaseClass() d) getSuperClass() Answer: a) getSuperclass() Explanation: The getSuperclass() method in Java is used to obtain the superclass of a class using reflection. This method is part of the Class class and returns a

Java MCQ: Which utility method in Java Reflection is used to check if a class is an array type? a) isArray() b) isArrayType() c) checkArray() d) isArrayClass() Answer: a) isArray() Explanation: The isArray() method in Java is used to check if a class is an array type. This method is part of the Class class

Java MCQ: How can you access the enum constants of an enum type using Java Reflection? a) getEnumConstants() b) getEnumValues() c) getConstants() d) getEnums() Answer: a) getEnumConstants() Explanation: The getEnumConstants() method in Java is used to access the enum constants of an enum type using reflection. This method is part of the Class class and

Java MCQ: How can you retrieve the length of an array using Java Reflection? a) getArrayLength() b) length() c) getLength() d) arrayLength() Answer: c) getLength() Explanation: The getLength() method in the java.lang.reflect.Array class is used to retrieve the length of an array using Java Reflection. This method is particularly useful when working with arrays of

Java MCQ: Which method is used to create an instance of a class using its constructor with Java Reflection? a) newInstance() b) create() c) construct() d) build() Answer: a) newInstance() Explanation: The newInstance() method in Java is used to create a new instance of a class using its constructor via reflection. This method is part

Java MCQ: Which method is used to access a private field using Java Reflection? a) getField() b) getDeclaredField() c) getPrivateField() d) accessField() Answer: b) getDeclaredField() Explanation: The getDeclaredField() method in Java is used to access a private field of a class using reflection. This method is part of the Class class and returns a Field

Java MCQ: Which method is used to invoke a method on an object using Java Reflection? a) invokeMethod() b) call() c) execute() d) invoke() Answer: d) invoke() Explanation: The invoke() method in Java is used to invoke a method on an object using reflection. This method is part of the Method class, which is found

Java MCQ: Which class is used to obtain information about a class in Java Reflection? a) ClassInfo b) ClassInspector c) Class d) ReflectionClass Answer: c) Class Explanation: The Class class in Java is the primary class used to obtain information about a class in Java Reflection. The Class class is part of the java.lang package

Java MCQ: What is the primary purpose of the Java Reflection API? a) To allow code reusability b) To enable dynamic inspection and manipulation of classes, methods, and fields at runtime c) To improve performance d) To simplify syntax Answer: b) To enable dynamic inspection and manipulation of classes, methods, and fields at runtime Explanation:

Java MCQ: Which class is used to compress files into ZIP format in Java? a) ZipOutputStream b) ZipFile c) ZipCompressor d) ZipWriter Answer: a) ZipOutputStream Explanation: The ZipOutputStream class in Java is used to compress files into the ZIP format. It is part of the java.util.zip package and provides methods to write compressed data to