corejava1

1. what is "Tiger" in java?

Answer :- no need worry, it's just regarding version names given
J2SE 5.0 (1.5.0) --> Tiger
you can check other version names also

2. default size of Hashmap,Hashtable,Arraylist & Hashset?

Answer :-
Hashmap = 16
Hashtable = 11
Arraylist = 10
Hashset = 16

3. How to change load factor?

Answer :- we have overloaded constructors for this.
for example,- to change load factor of Hashmap
use Hashmap<Key,Value>(initial capacity,load factor)
and pass values

4. How Size increament done for ArrayList and vector?

Answer :- 
for ArrayList ==> 50% after load factor
for vector ==> double size after load factor

5. How to traverse List in both direction?

Answer :-
use ListIterator having methods:-
addFirst(),addLast()
removeFirst(),removeLast()
getFirst(),getLast()