What is the concept of Immutability for strings in Java Why are strings immutable

0 votes

Why is it that they decided to make string immutable in Java and .NET (and some other languages)? Why didn't they make it mutable?

May 11, 2018 in Java by Parth
• 4,640 points
1,616 views

1 answer to this question.

0 votes

According to Effective Java, chapter 4, page 73, 2nd edition:

"There are many good reasons for this: Immutable classes are easier to design, implement, and use than mutable classes. They are less prone to error and are more secure.

[...]

"Immutable objects are simple. An immutable object can be in exactly one state, the state in which it was created. If you make sure that all constructors establish class invariants, then it is guaranteed that these invariants will remain true for all time, with no effort on your part.

[...]

Immutable objects are inherently thread-safe; they require no synchronization. They cannot be corrupted by multiple threads accessing them concurrently. This is far and away the easiest approach to achieving thread safety. In fact, no thread can ever observe any effect of another thread on an immutable object. Therefore, immutable objects can be shared freely

[...]

Other small points from the same chapter:

Not only can you share immutable objects, but you can share their internals.

[...]

Immutable objects make great building blocks for other objects, whether mutable or immutable.

[...]

The only real disadvantage of immutable classes is that they require a separate object for each distinct value.

answered May 11, 2018 by Rishabh
• 3,620 points

Related Questions In Java

0 votes
1 answer

What are the different ways of comparing Strings in Java?

The different ways of comparing string in ...READ MORE

answered Mar 5, 2019 in Java by Wasim
1,016 views
0 votes
2 answers

What is the use of @Override annotation in Java ? When do we use it ?

@Override annotation is used when we override ...READ MORE

answered Aug 14, 2019 in Java by Sirajul
• 59,230 points
3,487 views
0 votes
2 answers

What is the use of final class in java?

In Java, items with the final modifier cannot be ...READ MORE

answered Oct 5, 2018 in Java by Daisy
• 8,140 points
1,915 views
0 votes
1 answer

What is the use of StringBuilder in java?

If you use String concatenation in a ...READ MORE

answered Jun 19, 2018 in Java by Akrati
• 960 points
815 views
0 votes
3 answers

Check if a String is numeric in Java

Java 8 Lambda Expression is used: String someString ...READ MORE

answered Sep 3, 2018 in Java by Daisy
• 8,140 points
3,718 views
0 votes
2 answers

Generate an alpha-numeric string randomly

Java supplies a way of doing this ...READ MORE

answered Jul 18, 2018 in Java by Daisy
• 8,140 points
2,648 views
0 votes
1 answer

How do I create a Java string from the contents of a file?

If you're looking for an alternative that ...READ MORE

answered Apr 19, 2018 in Java by Rishabh
• 3,620 points
1,204 views
0 votes
2 answers

Counting no of Occurrence of a particular character inside a string in Java

We can find out the no. of ...READ MORE

answered Sep 7, 2018 in Java by Sushmita
• 6,920 points
2,804 views
0 votes
2 answers

What is the use of toString method in Java and how can I use it ?

Whenever you require to explore the constructor ...READ MORE

answered Aug 23, 2018 in Java by Daisy
• 8,140 points
4,123 views
0 votes
1 answer

What is the 'instanceof' operator used for in Java?

It's an operator that returns true if ...READ MORE

answered May 23, 2018 in Java by Rishabh
• 3,620 points
1,097 views
webinar REGISTER FOR FREE WEBINAR X
REGISTER NOW
webinar_success Thank you for registering Join Edureka Meetup community for 100+ Free Webinars each month JOIN MEETUP GROUP