What are the differences between a HashMap and a Hashtable in Java

0 votes
What are the differences between a HashMap and a Hashtable in Java?

Which is more efficient for non-threaded applications?
Dec 21, 2020 in Java by Rajiv
• 8,910 points
161 views

1 answer to this question.

0 votes

There are several differences between HashMap and Hashtable in Java:

  1. Hashtable is synchronized, whereas HashMap is not. This makes HashMap better for non-threaded applications, as unsynchronized Objects typically perform better than synchronized ones.

  2. Hashtable does not allow null keys or values. HashMap allows one null key and any number of null values.

  3. One of HashMap's subclasses is LinkedHashMap, so in the event that you'd want predictable iteration order (which is insertion order by default), you could easily swap out the HashMap for a LinkedHashMap. This wouldn't be as easy if you were using Hashtable.

Since synchronization is not an issue for you, I'd recommend HashMap. If synchronization becomes an issue, you may also look at ConcurrentHashMap.

answered Dec 21, 2020 by Gitika
• 65,970 points

Related Questions In Java

0 votes
2 answers

What is the difference between Map and HashMap in java?

The basic difference is : Map is ...READ MORE

answered Aug 28, 2019 in Java by Sirajul
• 59,090 points
22,718 views
0 votes
2 answers

What is the difference between Set and List in java?

LIST SET Duplicates YES NO Order Ordered Depends on Implementation Positional Access YES NO List is an ordered sequence ...READ MORE

answered Aug 14, 2019 in Java by Sirajul
• 59,090 points
9,367 views
0 votes
2 answers

What is the difference between getAttribute() and getParameter() in java?

getParameter() returns http request parameters. Those passed from ...READ MORE

answered Aug 28, 2019 in Java by Sirajul
• 59,090 points
12,679 views
0 votes
2 answers

What is the difference between Type List and type ArrayList in Java

By List, you actually tell, that your object ...READ MORE

answered Aug 28, 2019 in Java by Sirajul
• 59,090 points
943 views
0 votes
2 answers

How is hashmap different from hashtable?

HashMap and HashTable: 1) Hashtable and Hashmap implement ...READ MORE

answered Aug 1, 2018 in Java by samarth295
• 2,220 points
3,117 views
0 votes
2 answers

Ho do I Iterate through a HashMap which contains duplicate values

for (Map.Entry<String, String> item : params.entrySet()) { ...READ MORE

answered Jul 24, 2018 in Java by samarth295
• 2,220 points
2,177 views
0 votes
2 answers

Performing Iteration over each entry in a 'Map'

In Java 8 you can do it ...READ MORE

answered Oct 24, 2018 in Java by Sushmita
• 6,900 points
276 views
0 votes
2 answers
+1 vote
7 answers

What is difference between access modifier and access specifier in java

Access Specifier:- This can be understood as ...READ MORE

answered Feb 14, 2019 in Java by Priyaj
• 58,140 points
36,677 views
+1 vote
4 answers

What is a simple way to repeat a string in java?

There is already answer wriiten using StringBuilder ...READ MORE

answered Dec 16, 2020 in Java by Rajiv
• 8,910 points
24,358 views