what is the difference between HashMap and Hashtable
- 17 Answers
- 60147 Views
- Value Labs, Virtusa, I also Faced
- E-Mail Answers
Answers were Sorted based on User's Feedback
Answer / brijendra kumar soni(xavient)
1-Hashmap is nonSyncronized whereas Hastable is Syncronized.
2-Hashmap allows both key and values are Null whereas
Hastable doesnot allow Null values.
3-Hasmap belongs to Collection package whereas Hashtable is
a class.
4-The class Hashmap implements the map interface whereas
Hastable implements the class.
| Is This Answer Correct ? | 1 Yes | 0 No |
Answer / avinash
1. Hash map is not is synchornized
2. Hash map is allow null value only at once.
3. iterator is fail safe
1.Hash table is synchronized.
2. Hash table isnot allow null value.
3. enum hashtable is not.
| Is This Answer Correct ? | 1 Yes | 0 No |
Answer / rohit
Hash table is Synchronized whereas Hash map is Asynchronized.
Hash Map allows one null key and multiple null values
whereas Hash Table does not allow null...
| Is This Answer Correct ? | 1 Yes | 0 No |
Answer / jyotsna gupta
1. Hashtable is synchronized where as hashmap is not.
2. Hashmap can contains null values as the keys and as well as values.But Hashtable dose not allow null values as keys and values.
3. Another difference is that iterator in the HashMap is fail-safe while the enumerator for the Hashtable isn't. If you change the map while iterating, you'll know.
4. Hashmap is faster than Hashtable.
| Is This Answer Correct ? | 2 Yes | 2 No |
Answer / chandan
The key difference between the two is that access to the
Hashtable is synchronized on the table while access to the
HashMap isn't. You can add it, but it isn't there by default.
Another difference is that iterator in the HashMap is
fail-safe while the enumerator for the Hashtable isn't. If
you change the map while iterating, you'll know.
And, a third difference is that HashMap permits null values
in it, while Hashtable doesn't.
| Is This Answer Correct ? | 0 Yes | 0 No |
Answer / tarun kumar
class Hashtable was part of the original java.util and is a
concreate implementation of a Dictionary class. In java2 it
is reengineering it so that it also implements the Map
interface.
Thus it is now integrated into the collections framework.
class HashMap implements Map interface.
Because, Hashtable is a concreate implementation of
Dictionary class, is Legacy class, all legacy classes are
synchronized. So,thats why Hashtable is sunchronized.
I can say that both Hashtable and HashMap are same, accept
synchronization.
| Is This Answer Correct ? | 22 Yes | 25 No |
what is the main difference between string and stringbuffer? can you explain it with program?
Why do we need singleton class?
I don’t want my class to be inherited by any other class. What should I do?
Can we catch more than one exception in a single catch block?
Name some classes present in java.util.regex package.
Does A Class Inherit The Constructors Of Its Superclass?
What is a Java package and how is it used?
How does split work in java?
Is null a string?
what is java bean?where can we use it?
In what ways you can handle exception ?
what is the Diff. between Access Specifiers and Access Modifiers?
39 Answers BMC, Cyber Shot, Infosys, VTS, Wipro,
Core Java 
