What Are the Differences Between String and StringBuffer

[JiaPei Jen]

Both String and StringBuffer are final classes. StringBuffer grows in size dynamically. Could people help to detail other differences between String and StringBuffer?

[Charlie Goth]

The value in a StringBuffer can be changed/altered by calls to its methods (append, insert etc.), whereas a String's value can never change.
Appending to a StringBuffer is a lot more efficient that adding multiple String together.

[kapil munjal]

Yes the main difference is that String is immutable and StringBuffer is mutable.

Kaps

[K Anshul]

Objects of type String are read only and immutable. When u try to change a string object what actually happens is that a new strign is created.
The StringBuffer class is used to represent characters that can be modified.

The performance difference between these two classes is that StringBuffer is faster than String when performing simple concatenations.

[natarajan raman]

Hi,

You can go through the following link to understand the difference better.

http://www.whizlabs.com/tutorial/scjp/j-scjp-9-2.html

I am sure it would help you.
[ July 09, 2004: Message edited by: natarajan raman ]

[Raza Taqi]

Respected Friend,
Herbert Schildt in his book "The Complete Reference Java 2" explined the difference as follows :

"StringBuffer is a peer class of String that provides much more functionality of strings.As you know String represents fixed length,immutable characters sequences.In contrast,StringBuffer represents growable and writeable characters sequences.StringBuffer may have characters and sub strings inserted in the middle or appended to the end.StringBuffer will automatically grow to make room for such additions and often have more characters pre allocated than are actually needed,to allow room for growth.Java uses both classes heavily,but many programmers deal only with String and let Java manipulate StringBuffers behind the scenes by using the overloaded + operator".

Taqi Raza
[email protected]