Java MCQs.pdf
- 1. JAVA - MCQs By www.iteagers.com - Visit for more mcqs 1. What is encapsulation? A. Data hiding B. Inheritance C. Polymorphism D. Abstraction 2. What is the main purpose of inheritance in OOP? A. Code reuse B. Data hiding C. Encapsulation D. Polymorphism 3. Which OOP principle refers to the ability of a class to have multiple methods with the same name but different parameters? A. Encapsulation B. Polymorphism C. Inheritance D. Abstraction 4. What does the term "abstraction" mean in OOP? A. Data hiding B. Code reuse C. Simplifying complexity D. Inheritance 5. In OOP, what is a class? A. Object instance B. Method definition C. Blueprint for objects D. Variable declaration 6. What is the purpose of the "super" keyword in Java? A. Reference to the current object B. Reference to the superclass
- 2. C. Reference to the subclass D. Reference to the base class 7. What is method overloading in Java? A. Writing multiple methods with the same name but different parameters B. Writing multiple methods with the same name and same parameters C. Writing multiple methods in different classes D. Writing methods with different names and parameters 8. Which OOP principle allows a class to implement multiple interfaces? A. Inheritance B. Encapsulation C. Polymorphism D. Interface Segregation 9. What is the role of the "this" keyword in Java? A. Reference to the current object B. Reference to the superclass C. Reference to the subclass D. Reference to the base class 10. What is dynamic polymorphism in Java? A. Compile-time polymorphism B. Runtime polymorphism C. Operator overloading D. Method overloading 11. What is the purpose of the "final" keyword in Java? A. To declare a constant B. To prevent method overriding C. To prevent class inheritance D. All of the above 12. What is composition in OOP? A. Inheriting from multiple classes B. Creating objects within objects C. Using interfaces D. Dynamic polymorphism 13. What is the difference between aggregation and composition? A. Aggregation implies stronger relationships B. Composition implies stronger relationships
- 3. C. Aggregation involves creating objects within objects D. Composition involves a weaker relationship 14. What is the purpose of the "interface" in Java? A. To provide a code implementation B. To declare constants and variables C. To declare method signatures D. To create abstract classes 15. What is the role of the "abstract" keyword in Java? A. To create an abstract class B. To create an interface C. To create a concrete class D. To declare abstract methods 16. What is the difference between method overloading and method overriding? A. Overloading is static polymorphism B. Overriding is static polymorphism C. Overloading is dynamic polymorphism D. Overriding is dynamic polymorphism 17. What is a constructor in Java? A. A method with a void return type B. A method with the same name as the class C. A special method for object initialization D. A method with a static keyword 18. What is the purpose of the "clone" method in Java? A. To create a copy of an object B. To clone an entire class C. To create an object of a class D. To copy a class definition 19. How does Java support multiple inheritances? A. Through class inheritance B. Through interface inheritance C. Through method inheritance D. Through abstract class inheritance 20. What is the purpose of the "instanceof" operator in Java? A. Checking if an object is an instance of a specific class B. Checking if a class is abstract C. Checking if a class is final
- 4. D. Checking if an object is null 21. What is the Java platform? A. Compiler and editor B. Operating system and hardware C. JVM, libraries, and APIs D. Web browser and plugins 22. Which component of the Java platform is responsible for executing Java bytecode? A. Compiler B. JVM (Java Virtual Machine) C. API (Application Programming Interface) D. JRE (Java Runtime Environment) 23. What is the purpose of the Java API (Application Programming Interface)? A. To provide a development environment B. To execute Java bytecode C. To define the Java language syntax D. To provide pre-built functionality 24. Which part of the Java platform is platform-independent? A. Compiler B. JVM (Java Virtual Machine) C. Libraries D. Operating system 25. What is the purpose of the JRE (Java Runtime Environment)? A. To compile Java source code B. To run Java applications C. To develop Java programs D. To provide Java documentation 26. Which component of the Java platform is responsible for translating Java source code into bytecode? A. JVM (Java Virtual Machine) B. JRE (Java Runtime Environment) C. Compiler D. API (Application Programming Interface) 27. What is the purpose of the "classpath" in Java?
- 5. A. To specify the location of the JDK B. To define the path of the Java compiler C. To specify the location of Java libraries D. To set the location of Java source files 28. What is the main function of the JIT compiler in the JVM? A. Translating Java source code to bytecode B. Translating bytecode to machine code C. Optimizing and compiling bytecode D. Interpreting Java bytecode 29. Which tool is used to create executable JAR files in Java? A. javac B. jar C. java D. javadoc 3. What is the purpose of the "javac" command in Java? A. To run Java applications B. To compile Java source code C. To create JAR files D. To execute Java bytecode 31. What is the bytecode in Java? A. Machine-specific code B. Source code C. Intermediary code D. Executable code 32. Which tool is used to generate Java documentation? A. javac B. jar C. javadoc D. java 33. What is the purpose of the "java" command in Java? A. To compile Java source code B. To create JAR files C. To execute Java applications D. To generate Java documentation 34. What is the primary role of the Java Native Interface (JNI)? A. To provide a graphical user interface
- 6. B. To integrate Java with native code C. To optimize Java bytecode D. To create platform-independent code 35. What is the purpose of the "java.lang" package in Java? A. To provide basic language support B. To handle file I/O operations C. To create graphical user interfaces D. To perform network operations 36. What is the role of the "classpath" in Java? A. To define the path of the Java compiler B. To specify the location of the JDK C. To set the location of Java source files D. To specify the location of Java libraries 37. What is the purpose of the "assert" statement in Java? A. To handle exceptions B. To control program flow C. To perform assertions D. To declare constants 38. What is the difference between the JVM and the JRE? A. The JVM includes the compiler B. The JRE includes the compiler C. The JVM includes the libraries D. The JRE includes the bytecode interpreter 39. Which method is called when an object is garbage collected? A. finalize() B. delete() C. clean() D. collect() 40. What is the purpose of the "javap" tool in Java? A. To disassemble Java bytecode B. To analyze Java source code C. To compile Java source code D. To execute Java applications 41. What is the role of the JVM (Java Virtual Machine) in Java? A. Converts Java source code to bytecode B. Executes Java bytecode
- 7. C. Compiles Java source code D. Translates bytecode to machine code 42. What is the purpose of the "java" command in Java? A. Compiles Java source code B. Creates JAR files C. Executes Java applications D. Generates Java documentation 43. Which component of the Java platform houses the JVM? A. JRE (Java Runtime Environment) B. JDK (Java Development Kit) C. Java API D. Java Compiler 44. How does the JVM achieve platform independence? A. By converting Java source code to machine code B. By interpreting Java bytecode C. By using native code D. By relying on the operating system's compiler 45. What is the role of the Just-In-Time (JIT) compiler in the JVM? A. Translates Java source code to bytecode B. Translates bytecode to machine code C. Optimizes and compiles bytecode D. Interprets Java bytecode 46. What is the bytecode in Java? A. Machine-specific code B. Source code C. Intermediary code D. Executable code 47. How does the JVM handle memory management? A. Manual memory allocation B. Automatic garbage collection C. Dynamic memory allocation D. Both B and C 48. Which memory area of the JVM stores the runtime constant pool? A. Method Area B. Heap C. Stack
- 8. D. Native Method Stack 49. What is the purpose of the "javap" tool in Java? A. To disassemble Java bytecode B. To analyze Java source code C. To compile Java source code D. To execute Java applications 50. What is the stack memory used for in the JVM? A. Storing objects and variables B. Storing method calls C. Storing class definitions D. Storing constant values For more mcqs please visit: www.iteagers.com Computer MCQs - ITEagers 500+ Java Mcqs 500+ Networking Mcqs 500+ Operating System Mcqs 500+ Data Structure Mcqs 500+ MS Office Mcqs 500+ Database Mcqs 500+ PHP Mcqs 500+ Artificial Intelligence 500+ Python Mcqs 500+ C Language Mcqs 500+ C++ Mcqs 500+ SQL Server Mcqs