GeeksforGeeks

Explain the need for "Virtual Destructor".

Differences between class and structure?

difference between overloading and overriding?

Make a class diagram for thread-pool. Also discuss how to allocate threads for different calls.

Write a class for finding next element in preorder traversal of a binary tree. You can't modify the basic structure of tree. Also discuss about your algorithm.

Whats the difference between an interface and a abstract class?

Does Java allow you to have private or protected constructors?

Consider a scenario where lots of objects are created in runtime and soon after the execution starts, you have millions of objects consuming 90% of JVM memory. What would you do about it?

Explain the difference between overloading and overriding?