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MCQOPTIONS
This section includes 1671 Mcqs, each offering curated multiple-choice questions to sharpen your Technical Programming knowledge and support exam preparation. Choose a topic below to get started.
| 1451. |
What is true about Class.getInstance()? |
| A. | Class.getInstance calls the constructor |
| B. | Class.getInstance is same as new operator |
| C. | Class.getInstance needs to have matching constructor |
| D. | Class.getInstance creates object if class does not have any constructor |
| Answer» E. | |
| 1452. |
What is false about constructor? |
| A. | Constructors cannot be synchronized in Java |
| B. | Java does not provide default copy constructor |
| C. | Constructor can be overloaded |
| D. | “this” and “super” can be used in a constructor |
| Answer» D. “this” and “super” can be used in a constructor | |
| 1453. |
What would be the behaviour if this() and super() used in a method? |
| A. | Runtime error |
| B. | Throws exception |
| C. | compile time error |
| D. | Runs successfully |
| Answer» D. Runs successfully | |
| 1454. |
What is true about private constructor? |
| A. | Private constructor ensures only one instance of a class exist at any point of time |
| B. | Private constructor ensures multiple instances of a class exist at any point of time |
| C. | Private constructor eases the instantiation of a class |
| D. | Private constructor allows creating objects in other classes |
| Answer» B. Private constructor ensures multiple instances of a class exist at any point of time | |
| 1455. |
What is the output of this program? 1. class area 2. { 3. int width; 4. int length; 5. int area; 6. void area(int width, int length) 7. { 8. this.width = width; 9 this.length = length; 10. } 11. } 12. class Output 13. { 14. public static void main(String args[]) 15. { 16. area obj = new area(); 17. obj.area(5 , 6); 18. System.out.println(obj.length + " " + obj.width); 19. } 20. } |
| A. | 0 0 |
| B. | 5 6 |
| C. | 6 5 |
| D. | 5 5 |
| Answer» D. 5 5 | |
| 1456. |
Which of the following statements are incorrect? |
| A. | default constructor is called at the time of object declaration |
| B. | Constructor can be parameterized |
| C. | finalize() method is called when a object goes out of scope and is no longer needed |
| D. | finalize() method must be declared protected |
| Answer» D. finalize() method must be declared protected | |
| 1457. |
What is the output of this program? 1. class box 2. { 3. int width; 4. int height; 5. int length; 6. int volume; 7. void finalize() 8. { 9. volume = width*height*length; 10. System.out.println(volume); 11. } 12. protected void volume() 13. { 14. volume = width*height*length; 15. System.out.println(volume); 16. } 17. } 18. class Output 19. { 20. public static void main(String args[]) 21. { 22. box obj = new box(); 23. obj.width=5; 24. obj.height=5; 25. obj.length=6; 26. obj.volume(); 27. } 28. } |
| A. | 150 |
| B. | 200 |
| C. | Run time error |
| D. | Compilation error |
| Answer» B. 200 | |
| 1458. |
What is the output of this program? 1. class San 2. { 3. San()throws IOException 4. { 5. } 6. } 7. class Foundry extends San 8. { 9. Foundry() 10. { 11. } 12. public static void main(String[]args) 13. { 14. } 15. } |
| A. | compile time error |
| B. | run time error |
| C. | compile and runs fine |
| D. | unreported exception java.io.IOException in default constructor |
| Answer» B. run time error | |
| 1459. |
1. class box 2. { 3. int width; 4. int height; 5. int length; 6. int volume; 7. box() 8. { 9. width = 5; 10. height = 5; 11. length = 6; 12. } 13. void volume() 14. { 15. volume = width*height*length; 16. } 17. } 18. class constructor_output 19. { 20. public static void main(String args[]) 21. { 22. box obj = new box(); 23. obj.volume(); 24. System.out.println(obj.volume); 25. } 26. } |
| A. | 100 |
| B. | 150 |
| C. | 200 |
| D. | 250 |
| Answer» C. 200 | |
| 1460. |
Which function is used to perform some action when the object is to be destroyed? |
| A. | finalize() |
| B. | delete() |
| C. | main() |
| D. | none of the mentioned |
| Answer» B. delete() | |
| 1461. |
Which operator is used by Java run time implementations to free the memory of an object when it is no longer needed? |
| A. | delete |
| B. | free |
| C. | new |
| D. | none of the mentioned |
| Answer» E. | |
| 1462. |
Which of the following is a method having same name as that of its class? |
| A. | finalize |
| B. | delete |
| C. | class |
| D. | constructor |
| Answer» E. | |
| 1463. |
Which keyword is used by method to refer to the object that invoked it? |
| A. | import |
| B. | catch |
| C. | abstract |
| D. | this |
| Answer» E. | |
| 1464. |
What is the return type of Constructors? |
| A. | int |
| B. | float |
| C. | void |
| D. | none of the mentioned |
| Answer» E. | |
| 1465. |
What is the output of this program? class area { int width; int length; int volume; area() { width=5; length=6; } void volume() { volume = width*length*height; } } class cons_method { public static void main(String args[]) { area obj = new area(); obj.volume(); System.out.println(obj.volume); } } |
| A. | 0 |
| B. | 1 |
| C. | 30 |
| D. | error |
| Answer» E. | |
| 1466. |
In the below code, which call to sum() method is appropriate? class Output { public static int sum(int ...x) { return; } static void main(String args[]) { sum(10); sum(10,20); sum(10,20,30); sum(10,20,30,40); } } |
| A. | only sum(10) |
| B. | only sum(10,20) |
| C. | only sum(10) & sum(10,20) |
| D. | all of the mentioned |
| Answer» E. | |
| 1467. |
What is the output of this program? class box { int width; int height; int length; int volume; void volume() { volume = width*height*length; } } class Output { public static void main(String args[]) { box obj = new box(); obj.height = 1; obj.length = 5; obj.width = 5; obj.volume(); System.out.println(obj.volume); } } |
| A. | 0 |
| B. | 1 |
| C. | 25 |
| D. | 26 |
| Answer» D. 26 | |
| 1468. |
What is the output of this program? class equality { int x; int y; boolean isequal() { return(x == y); } } class Output { public static void main(String args[]) { equality obj = new equality(); obj.x = 5; obj.y = 5; System.out.println(obj.isequal()); } } |
| A. | false |
| B. | true |
| C. | 0 |
| D. | 1 |
| Answer» C. 0 | |
| 1469. |
What is the output of this program? class box { int width; int height; int length; int volume; void volume(int height, int length, int width) { volume = width*height*length; } } class Prameterized_method { public static void main(String args[]) { box obj = new box(); obj.height = 1; obj.length = 5; obj.width = 5; obj.volume(3,2,1); System.out.println(obj.volume); } } |
| A. | 0 |
| B. | 1 |
| C. | 6 |
| D. | 25 |
| Answer» D. 25 | |
| 1470. |
Which method can be defined only once in a program? |
| A. | main method |
| B. | finalize method |
| C. | static method |
| D. | private method |
| Answer» B. finalize method | |
| 1471. |
Which of the following is a method having same name as that of it’s class? |
| A. | finalize |
| B. | delete |
| C. | class |
| D. | constructor |
| Answer» E. | |
| 1472. |
What is the process of defining more than one method in a class differentiated by method signature? |
| A. | Function overriding |
| B. | Function overloading |
| C. | Function doubling |
| D. | None of the mentioned |
| Answer» C. Function doubling | |
| 1473. |
What is the return type of a method that does not returns any value? |
| A. | int |
| B. | float |
| C. | void |
| D. | double |
| Answer» D. double | |
| 1474. |
What is the output of this program? class box { int width; int height; int length; } class mainclass { public static void main(String args[]) { box obj = new box(); System.out.println(obj); } } |
| A. | 0 |
| B. | 1 |
| C. | Runtime error |
| D. | classname@hashcode in hexadecimal form |
| Answer» E. | |
| 1475. |
What is the output of this program? class box { int width; int height; int length; } class mainclass { public static void main(String args[]) { box obj1 = new box(); box obj2 = new box(); obj1.height = 1; obj1.length = 2; obj1.width = 1; obj2 = obj1; System.out.println(obj2.height); } } |
| A. | 1 |
| B. | 2 |
| C. | Runtime error |
| D. | Garbage value |
| Answer» B. 2 | |
| 1476. |
What is the output of this program? class box { int width; int height; int length; } class mainclass { public static void main(String args[]) { box obj = new box(); obj.width = 10; obj.height = 2; obj.length = 10; int y = obj.width * obj.height * obj.length; System.out.print(y); } } |
| A. | 12 |
| B. | 200 |
| C. | 400 |
| D. | 100 |
| Answer» C. 400 | |
| 1477. |
Which of the following statements is correct? |
| A. | Public method is accessible to all other classes in the hierarchy |
| B. | Public method is accessible only to subclasses of its parent class |
| C. | Public method can only be called by object of its class |
| D. | public method can be accessed by calling object of the public class |
| Answer» B. Public method is accessible only to subclasses of its parent class | |
| 1478. |
What is the output of this program? class main_class { public static void main(String args[]) { int x = 9; if (x == 9) { int x = 8; System.out.println(x); } } } |
| A. | 9 |
| B. | 8 |
| C. | Compilation error |
| D. | Runtime error |
| Answer» D. Runtime error | |
| 1479. |
Which of these operators is used to allocate memory for an object? |
| A. | malloc |
| B. | alloc |
| C. | new |
| D. | give |
| Answer» D. give | |
| 1480. |
Which of the following is a valid declaration of an object of class Box? |
| A. | Box obj = new Box(); |
| B. | Box obj = new Box; |
| C. | Box obj = new Box; |
| D. | new Box obj; |
| Answer» B. Box obj = new Box; | |
| 1481. |
Which of these keywords is used to make a class? |
| A. | class |
| B. | struct |
| C. | int |
| D. | none of the mentioned |
| Answer» B. struct | |
| 1482. |
What is the stored in the object obj in following lines of code? box obj; |
| A. | Memory address of allocated memory of object |
| B. | NULL |
| C. | Any arbitrary pointer |
| D. | Garbage |
| Answer» C. Any arbitrary pointer | |
| 1483. |
What is use of interpreter? |
| A. | They convert bytecode to machine language code |
| B. | They read high level code and execute them |
| C. | They are intermediated between JIT and JVM |
| D. | They are intermediated between JIT and JVM |
| Answer» C. They are intermediated between JIT and JVM | |
| 1484. |
How can we identify whether a compilation unit is class or interface from a .class file? |
| A. | Java source file header |
| B. | Extension of compilation unit |
| C. | We cannot differentiate between class and interface |
| D. | The class or interface name should be postfixed with unit type |
| Answer» B. Extension of compilation unit | |
| 1485. |
What is the extension of compiled java classes? |
| A. | .class |
| B. | .java |
| C. | .txt |
| D. | .js |
| Answer» B. .java | |
| 1486. |
What is the extension of java code files? |
| A. | .class |
| B. | .java |
| C. | .txt |
| D. | .js |
| Answer» C. .txt | |
| 1487. |
Which of the below is invalid identifier with main method? |
| A. | public |
| B. | Static |
| C. | private |
| D. | Final |
| Answer» D. Final | |
| 1488. |
Which statement is true about java? |
| A. | Platform independent programming language |
| B. | Platform dependent programming language |
| C. | Code dependent programming language |
| D. | Sequence dependent programming language |
| Answer» B. Platform dependent programming language | |
| 1489. |
Which component is responsible to optimize bytecode to machine code? |
| A. | JVM |
| B. | JDK |
| C. | JIT |
| D. | JRE |
| Answer» D. JRE | |
| 1490. |
Which component is responsible to run java program? |
| A. | JVM |
| B. | JDK |
| C. | JIT |
| D. | JRE |
| Answer» E. | |
| 1491. |
Which component is responsible for converting bytecode into machine specific code? |
| A. | JVM |
| B. | JDK |
| C. | JIT |
| D. | JRE |
| Answer» B. JDK | |
| 1492. |
Which component is used to compile, debug and execute java program? |
| A. | JVM |
| B. | JDK |
| C. | JIT |
| D. | JRE |
| Answer» C. JIT | |
| 1493. |
Method overriding is combination of inheritance and polymorphism? |
| A. | True |
| B. | False |
| Answer» B. False | |
| 1494. |
What is it called where object has its own lifecycle and child object cannot belong to another parent object? |
| A. | Aggregation |
| B. | Composition |
| C. | Encapsulation |
| D. | Association |
| Answer» B. Composition | |
| 1495. |
What is it called where child object gets killed if parent object is killed? |
| A. | Aggregation |
| B. | Composition |
| C. | Encapsulation |
| D. | Association |
| Answer» C. Encapsulation | |
| 1496. |
What is it called if an object has its own lifecycle and there is no owner? |
| A. | Aggregation |
| B. | Composition |
| C. | Encapsulation |
| D. | Association |
| Answer» E. | |
| 1497. |
Which concept of Java is achieved by combining methods and attribute into a class? |
| A. | Encapsulation |
| B. | Inheritance |
| C. | Polymorphism |
| D. | Abstraction |
| Answer» B. Inheritance | |
| 1498. |
Which concept of Java is a way of converting real world objects in terms of class? |
| A. | Polymorphism |
| B. | Encapsulation |
| C. | Abstraction |
| D. | Inheritance |
| Answer» D. Inheritance | |
| 1499. |
When Overloading does not occur? |
| A. | More than one method with same name but different method signature and different number or type of parameters |
| B. | More than one method with same name, same signature but different number of signature |
| C. | More than one method with same name, same signature, same number of parameters but different type |
| D. | More than one method with same name, same number of parameters and type but different signature |
| Answer» E. | |
| 1500. |
When does method overloading is determined? |
| A. | At run time |
| B. | At compile time |
| C. | At coding time |
| D. | At execution time |
| Answer» C. At coding time | |