MCQOPTIONS
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MCQOPTIONS
This section includes 12 Mcqs, each offering curated multiple-choice questions to sharpen your Java knowledge and support exam preparation. Choose a topic below to get started.
| 1. |
What would be behaviour if the constructor has a return type? |
| A. | Compilation error |
| B. | Runtime error |
| C. | Compilation and runs successfully |
| D. | Only String return type is allowed |
| Answer» B. Runtime error | |
| 2. |
What would be the behaviour if one parameterized constructor is explicitly defined? |
| A. | Compilation error |
| B. | Compilation succeeds |
| C. | Runtime error |
| D. | Compilation succeeds but at the time of creating object using default constructor, it throws compilation error |
| Answer» E. | |
| 3. |
What is true about protected constructor? |
| A. | Protected constructor can be called directly |
| B. | Protected constructor can only be called using super() |
| C. | Protected constructor can be used outside package |
| D. | protected constructor can be instantiated even if child is in a different package |
| Answer» C. Protected constructor can be used outside package | |
| 4. |
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. | |
| 5. |
What is false about constructor? |
| A. | Constructors cannot be synchronized in Java |
| B. | Java does not provide default copy constructor |
| C. | Constructor can have a return type |
| D. | “this” and “super” can be used in a constructor |
| Answer» D. “this” and “super” can be used in a constructor | |
| 6. |
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 | |
| 7. |
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 | |
| 8. |
Which of the following are implemented as classes containing constructor, destructor, copy constructor and overloaded assignment operator? |
| A. | float data type |
| B. | int data type |
| C. | all the above |
| D. | double data type |
| Answer» D. double data type | |
| 9. |
Which is used to make a copy of one class object from another class object of the same class type. |
| A. | copy constructor |
| B. | constructor |
| C. | default constructor |
| D. | destructor |
| Answer» B. constructor | |
| 10. |
WHAT_WOULD_BE_BEHAVIOUR_IF_THE_CONSTRUCTOR_HAS_A_RETURN_TYPE??$ |
| A. | Compilation error |
| B. | Runtime error |
| C. | Compilation and runs successfully |
| D. | Only String return type is allowed |
| Answer» B. Runtime error | |
| 11. |
What is not the use of “this” keyword in Java?$ |
| A. | Passing itself to another method |
| B. | Calling another constructor in constructor chaining |
| C. | Referring to the instance variable when local variable has the same name |
| D. | Passing itself to method of the same class |
| Answer» E. | |
| 12. |
Abstract class cannot have a constructor. |
| A. | True |
| B. | False |
| Answer» C. | |