Java MCQ Quiz (Part - 8 ) | infoStud blogs

Following quiz provides Multiple Choice Questions (MCQs) related to Core Java. You will have to read all the given answers and click over the correct answer. If you are not sure about the answer then you can check the answer using Show Answer button. You can use Next Quiz button to check new set of questions in the quiz

1. How can a method return a primitive value to the caller?

1. It can return the value to the caller by using the returnstatement.
2. It can assign the value to one of its parameters.
3. A method can under no circumstances communicate with the caller.
4. It can call its caller with the correct value.

2. If a method has a reference to an unchangeable object (eg string object), can the method then make a change to the object?

1. Yes, if she has a reference to the immutable object, she can change it.
2. No, only the generator of the immutable object can change it.
3. No, immutable objects can not be changed by anyone after they are created.
4. Yes, but she has to use the special “+” operator to do that.

3. Can a programmer (you) design a class whose objects are immutable?

1.Yes, by privatedeclaring all instance variables of the class as declared and no accessor methods.
2. No, only a few predefined Java classes Stringare immutable.
3. No, all predefined classes are immutable and all classes defined by the programmer are not.
4. Yes, by privatedeclaring all instance variables and methods as.

4. How many references can there be to a single object?

1. Just one.
2. Two. One from the caller and one from the called method.
3. There can be any number of references held in any number of variables and parameters (as long as they are of the correct type).
4. Three. The original reference and a reference for the formal and the current parameters.

5. Which operation is most often performed by programs?

1. Addition of the integer one to an integer variable.
2. Floating point division.
3. Construction of an object.
4. Access to the Internet.

6. Assume that there is three classes Computer, AppleComputerand IBMComputer. What does the relationship between these classes look like?

1. Computer, AppleComputerand IBMComputerare sibling classes.
2. IBMComputeris the superclass, AppleComputerand Computerare subclasses of IBMComputer.
3. Computeris the superclass, AppleComputerand IBMComputerare subclasses of Computer.
4. Computeris a superclass, AppleComputeris a subclass of Computerand IBMComputeris a subclass of AppleComputer.

7. Can an object be the subclass of another object?

1. No – inheritance exists only between classes.
2. Yes – as long as the single inheritance is observed.
3. Only if one is defined in the other’s terms.
4. Yes – when one object is used in the constructor of the other.

8. How many objects of a given class can be in a program?

1.As many as the program needs.
2. One per defined class.
3. One per constructor definition.
4. One per main()method.

9. What restriction is there when using the keyword superin a constructor?

1. It must be used as the first statement of the constructor.
2. It can only be used in the constructor of the superclass.
3. It can only be used by one subclass.
4. It must be used as the last statement of the constructor.

10.What is an abstract method?

1. An abstract method is any method in an abstract class.
2. An abstract method is a method that can not be inherited.
3. An abstract method is a bodyless method abstractdeclared with the reserved word .
4. An abstract method is a method in the subclass that overrides the method of a superclass.