HCLTech Interview Question
1. What you know about String? 2. Diff b/w String Buffer and String builder 3. Interfaces and implementations in the collection package 4. Create a thread class 5. Comparator vs comparable 6. Hashmap implementation 7. File read and update 8. Hashcode and equals method 9. HashSet vs Treeset 10. Pgm for palindrome check 11. Singleton class
Interview Answer
Anonymous
1. What you know about String? String is immutable, Perfect candidate for key in hashmap, String Pool, Why immutable. 2. Diff b/w String Buffer and String builder String buffer is thread safe, good for the strings with the many manipulations 3. Interfaces and implementations in the collection package Set - HashSet, TreeSet, LinkedHashSet, List - ArrayList, LinkedList, Vector(deprecated) Map - HashMap, TreeMap, LinkedHashMap, ConcurrentHashMap Queue, Dequeue - Blocking Queue, ArrayBlockingQueue, PriorityBlockingQueue SortedSet - TreeSet, TreeMap 4. Create a thread class implements Runnable. Why not Thread 5. Comparator vs comparable Comparable is natural way of sorting, comparator is own way of sorting. 6. Hashmap implementation Bucket and Linked list implementation 7. File read and update Pgm for reading and writing resume 8. Hashcode and equals method In the user defined class as a key in the map. We must to override the hashcode and equals method 9. HashSet vs Treeset 10. Pgm for palindrome check Using String buffer.reverse(), for(int i=0;i