program to demonstrate StringBuffer Functions:

class StringBufferTest

{

public static void main(String as[])

{

StringBuffer str= new StringBuffer(“Hello”);

//append()
str.append("World");

System.out.println(str); //prints HelloWorld

//insert()
str.insert(5,"_Java ");

System.out.println(str); //prints Hello_Java World

//reverse()
str.reverse();
System.out.print("Reversed string : ");
System.out.println(str); //prints dlroW avaJ_olleH
str.reverse();
System.out.println(str); //prints Hello_Java World

//setCharAt()
str.setCharAt(5,' ');
System.out.println(str); //prints Hello Java World
//charAt()
System.out.print("Character at 6th position : ");
System.out.println(str.charAt(6)); //prints J

//substring()
System.out.print("Substring from position 3 to 6 : ");
System.out.println(str.substring(3,7)); //prints lo J

//deleteCharAt()
str.deleteCharAt(3);
System.out.println(str); //prints Helo java World

//capacity()
System.out.print("Capacity of StringBuffer object : ");
System.out.println(str.capacity()); //prints 31
}

}