Difference between a String and a StringBuffer in Java
In Java, a
String is an immutable object that represents a sequence of characters. It means once a String is created, its value cannot be changed, any operation that appears to change the value of a String actually creates a new String object with the new value.
On the other hand, a
StringBuffer is a mutable object that also represents a sequence of characters. It means once a StringBuffer is created, its value can be changed, any operation that appears to change the value of a StringBuffer actually modifies the same object.
Here are a few key differences between
- Immutability: As mentioned before, a
Stringis immutable while a
- Performance: Because
Stringis immutable, every time you perform a concatenation operation on a
String, a new object is created. This can lead to poor performance if you’re concatenating many strings together.
StringBufferis mutable, so it can be modified in place, which is more efficient.
StringBufferis thread-safe, meaning it can be used in a multi-threaded environment without any additional synchronization. On the other hand,
Stringis not thread-safe.
StringBufferhas more methods than
String, for example,
In general, if you’re going to perform a lot of string concatenation or modification, you should use a
StringBuffer for better performance. If you’re working with a string that will not change, you should use a
in Java 1.5, a new class
StringBuilder is introduced, which is similar to
StringBuffer but is not thread-safe. If you don’t need thread-safety use
StringBuilder instead, it has the same performance as