Domanda di colloquio di Capgemini Engineering

1. Can we make interface variables as private? 2. Interface contains constructor or not? Can we create it there? 3. In Hash Map if we will not override HashCode and Equals methods than what will be the impact? 4. Explain oops features in details - Abstraction, Encapsulation, Polymorphism? 5. Why we use bean class in Java? 6. Internal working of Thread.start and Thread.run? 7. Difference between sleep and wait? 8. What if we write nothing in sleep method? 9. Custom Exception , can we use it with throw and throws, explain? 10. How to make a class Immutable? 11. Given two strings then WAP to tell strings are logically equals or not(both should contain same characters,frequency of characters can be different)? 12. WAP to Convert a decimal number into binary? 13. Difference between ArrayList and LinkedList? When to use which? 14. Difference between HashTable and HashMap? 15. What is AVT Tree? 16. Write code to implement BFS? 17. How can you strict the variables to not be serialized without using transient?