String object is immutable so that once it is created a String object cannot be changed. Since String is immutable it can safely be shared between many threads which are considered very important for multithreaded programming.

Q 5 - What is class variable?

A - class variables are static variables within a class but outside any method.

B - class variables are variables defined inside methods, constructors or blocks.

C - class variables are variables within a class but outside any method.

D - None of the above.

Answer : A

Explaination

Class variables are variables declared with in a class, outside any method, with the static keyword.

Q 6 - Can be constructor be made private?

A - True.

B - False.

Answer : A

Explaination

Yes, class with private constructor can not instantiated using new keyword.

Q 7 - Dynamic binding uses which information for binding?

A - type.

B - object.

C - Both of the above.

D - None of the above.

Answer : B

Explaination

Dynamic binding uses object information for binding.

Q 8 - What invokes a thread's run() method?

A - JVM invokes the thread's run() method when the thread is initially executed.

B - Main application running the thread.

C - start() method of the thread class.

D - None of the above.

Answer : A

Explaination

After a thread is started, via its start() method of the Thread class, the JVM invokes the thread's run() method when the thread is initially executed.

Q 9 - Is it necessary that each try block must be followed by a finally block?

A - True.

B - False.

Answer : B

Explaination

It is not necessary that each try block must be followed by a finally block. It should be followed by either a catch block or a finally block.

Q 10 - Which of the following is a marker interface?

A - serializable

B - comparable

C - cloneable

D - none of the above.

Answer : A

Explaination

serializable is a marker interface.

java_questions_answers.htm

Previous Page Print Page