Explain the difference between abstract class and interface in java?

982

Can we sort hashset in java?

1087

Can we call virtual funciton in a constructor ?

2197

Why are arrays useful in java?

1028

Explain the use of sublass in a java program?

1023

Explain about automatic type conversion in java?

1049

how to create multithreaded program? Explain different ways of using thread? When a thread is created and started, what is its initial state? Or extending thread class or implementing runnable interface. Which is better? : Java thread

1029

Name few "optional" classes introduced with java 8 ?

1134

Can an interface have a class?

1000

What do you mean by access modifier?

1026

What is Mutex (Mutual Exclusion Object) ?

1144

How do you trim a space in java?

979

Is set thread safe java?

920

what is mutual exclusion? How can you take care of mutual exclusion using java threads? : Java thread

1118

What is a singleton class? Give a practical example of its usage.

1100