In contrast to the String class which implements immutable character strings, the StringBuffer class implements mutable character strings. Not only can the character string in a string buffer gets changed, but the buffer’s capacity can also change dynamically. The capacity of a String Buffer is the maximum number of characters that a string buffer can accommodate, before its size is automatically augmented.

Both String and StringBuffer class are thread-safe.

The syntax for initializing String class object is: String str1=”Hello”;

The syntax for initializing StringBuffer class object is:

StringBuffer sbr1= new StringBuffer (“hello”);

StringBuffer sbr2= new StringBuffer (10);

StringBuffer sbr3= new StringBuffer();