Java Constructor Online Test - 2

1. What is true about constructor?

It can have any non access modifiers

It can contain return type

Constructor cannot throw an exception

It can take any number of parameters

2. What is not the use of "this" keyword in Java?

Passing itself to method of the same class

Passing itself to another method

Calling another constructor in constructor chaining

Referring to the instance variable when local variable has the same name

3. What is false about constructor?

"this" and "super" can be used in a constructor

Constructors cannot be synchronized in Java

Constructor can have a return type

Java does not provide default copy constructor

4. Abstract class cannot have a constructor.

False

True

5. What could be true about Class.getInstance() considering that it defines the getInstance() method?

Class.getInstance is same as new operator

Class.getInstance needs to have matching constructor

Class.getInstance calls the constructor

Class.getInstance creates object if class does not have any constructor

6. What would be behaviour if the constructor has a return type?

Compilation and runs successfully

Only String return type is allowed

Runtime error

Compilation error

7. What would be the behaviour if one parameterized constructor is explicitly defined?

Compilation succeeds

Compilation error

Compilation succeeds but at the time of creating object using default constructor, it throws compilation error

Runtime error

8. What would be the behaviour if this() and super() used in a method?

compile time error

Throws exception

Runtime error

Runs successfully

9. What is true about private constructor?

Private constructor allows creating objects in other classes

Private constructor ensures multiple instances of a class exist at any point of time

Private constructor eases the instantiation of a class

Private constructor ensures only one instance of a class exist at any point of time

10. What is true about protected constructor?

Protected constructor can only be called using super()

protected constructor can be instantiated even if child is in a different package

Protected constructor can be called directly

Protected constructor can be used outside package