Interested to Buy Any Domain ? << Click Here >> for more details...
what is Hashmap & Hashtable wirh example?
- 5 Answers
- 15008 Views
- CTS, Saksoft, I also Faced
- E-Mail Answers
Answers were Sorted based on User's Feedback
Answer / 20/04/2008
hashmap class is not syncronized but hasTable is syncronized
. both stores key and value. hashtable is part of legasy
class we can use enumerator interface of this hashtable class.
| Is This Answer Correct ? | 27 Yes | 3 No |
Answer / rameshreddy.k
---HashTable is synchronised BUT hashmap is not synchronised
---HashTable not allow null keys and null values BUT
HashMap allow only one null key and multiple null values
---HashTable not allow Duplicate keys and Douplicate values
are allowed.
| Is This Answer Correct ? | 12 Yes | 3 No |
Answer / leosun
Hashtable will not allow null key nor values,where as
Hashmap allows null key and values
| Is This Answer Correct ? | 14 Yes | 8 No |
Answer / venki
1. Hashtable is synchronized which means Hashtable is thread
safe and that can be shared with multiple threads (Suitable
for multi threaded applications), HashMap not synchronized
(Suitable for single threaded applications).
2. Iterator in the Hashtable is fail-fast iterator and throw
ConcurrentModificationException if any other thread modifies
the map by adding or removing elements from the Map, while
Emnumeration in HashMap not.
3. Hashtable is slower than HashMap because of synchronization.
4. HashTable does not allow null for both keys and values,
you will get NullPointerException if you add null. whereas
HashMap allows one null key and any number of null values.
5. Hashtable and HashMap allows duplicate values.
6. Hashtable store objects in insertion order but HashMap
doesn’t store objects in insertion order, to store objects
in insertion order use LinkedHashMap.
| Is This Answer Correct ? | 0 Yes | 1 No |
How do I get a substring?
How to convert String into primitive datatype.
if arraylist size is increased from initial size what is the size of arraylist...suppose initial is 100 , if i add 101 element what is the size...
Explain yield() method in thread class ?
What are singleton services?
Write an algorithm for quick sort?
What is final keyword?
Write a program to create a binary Tree ?
What is difference between static variable and global variable?
Iterator in the HashMap is fail-safe means what?
What are the advantages of java over C++?
What is java instanceof operator?
Core Java 
