Quest Global Senior Java Engineer interview questions

1. What is runtime polymorphism? Can you explain by writing and example ? 2. Developer d = new Employee(); Here employee is a super class and Developer is a subclass. If we can d.work(); which method will be executed? 3. Can we overload static methods ? 4. In the below array, move all the 0 to left and don't sort the remaining values: 3, 23,0,4,6,0,33,0,34 5. Reverse each string in the word and don't move the punctuations: "Hello, This is a String!" 6. What does a collision happen in Hashmap ? 7. What are different ways to create Thread ?? 8. What is the difference between synchronized block and synchronised method ?? Which is better with respect to performance? 9. If we have static block, a constructer and main method. What is the order of execution? 10. What are the design patterns that you have used in your project? 11. Can you write a program to display singleton design patterns? 12. What are the solid principles?