what is the difference between HashMap And HashTable?
- 5 Answers
- 11141 Views
- Hexaware, I also Faced
- E-Mail Answers
Answers were Sorted based on User's Feedback
Answer / ravikiran
HashMap allows one null key and multiple null values
HashTable doesnn't allow nulls
HashMap is not synchronized
hashtable is synchronized
| Is This Answer Correct ? | 13 Yes | 0 No |
Answer / stalin
The HashMap class is roughly equivalent to Hashtable, except
that it is unsynchronized and permits nulls. (HashMap allows
null values as key and value whereas Hashtable doesnt
allow). HashMap does not guarantee that the order of the map
will remain constant over time. HashMap is unsynchronized
and Hashtable is synchronized
| Is This Answer Correct ? | 8 Yes | 0 No |
Answer / guest
HashMap is a nonsyncronized and HashTable is a
syncronized.
| Is This Answer Correct ? | 7 Yes | 0 No |
Answer / venkateswarlu
HashMap :
->It is a key,value pair.
->key are not duplicated but values can be duplicated.
->Null key is possible.
->It is not Synchronized by default.
Hashtable:
->It is also key,value pair but both are Strings only.
-> Keys are not duplicated but values can be duplicated.
->Null insertion is not possible of both(key and value).
->It is Synchronized by default.
| Is This Answer Correct ? | 0 Yes | 0 No |
Answer / raghu
HashMap only one null key and multiple values. Hashtable
doesn't allow null keys and values, it throws
NullPointerException. Both are not guarantee order. HashMap
is unsyncronized, whereas Hashtable is not.
| Is This Answer Correct ? | 0 Yes | 1 No |
What do you know about the garbage collector?
Can you give few examples of final classes defined in java api?
What is volatile keyword in java
Is it possible to write static method in abstract class? justyfy your answer?
Explain the difference between an object-oriented programming language and object-based programming language?
What are parent methods and how can you call them?
Accenture NJ mostly ask question on Collection like 1)How to sort Objcts and how treeset sort them 2)Explain mechanism of Hashcode finding in Java 3)Name some of the Sorted collection.
What is audio clip interface? Name few methods of it ?
What is the base class of all classes?
What is the difference between java and .Net?
What is string length in java?
What are the methods available in a class?
Core Java 
