what is the difference between HashMap And HashTable?
- 5 Answers
- 11169 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 |
Marker interface means , interface which has no methods.Then what is the necessity of its usage.I read "it tells the compiler that it should be treated differently ". "It is used to store state of an object". But still am not clear.Please explain clearly.
Why is the main method static?
What is difference in between java class and bean?
why using interface interface ?
What are Normalization Rules? Define Normalization?
Is sizeof a preprocessor?
What technique is carried out to find out if a particular string is empty?
What is the properties class in java programming?
What is the use of parseint in java?
What are the advantages of the model over the event- inheritance model?
What is variable explain with example?
What is float in java?
Core Java 
