String In Java

public class StringBufferOperation{
    public static void main(String[] args){
        StringBuffer strBuf1 = new StringBuffer("Prashant");
        System.out.println("strBuf  " + strBuf1); //printing Prashant
        System.out.println("strBuf " + strBuf1.capacity());//16(default capacity) + 8 characters of 'Prashant' ie.24
        System.out.println("strBuf " + strBuf1.length());//showing length of string 'Prashant' ie. 8
        System.out.println("strBuf " + strBuf1.charAt(5));//showing character at position 5 ie. 0-5 ie.'a' in string 'Prashant'
       
        System.out.println("strBuf " + strBuf1.toString());//converts to a string representing the data in this string buffer.
       
       
       
        strBuf1.delete(3,5);
        System.out.println("strBuf " + strBuf1);//Printing Praant.
       
        strBuf1.insert(2,'c');
        System.out.println("strBuf " + strBuf1);// Printing Prashant as Prcashant
       
        strBuf1.setCharAt(0,'r');
        System.out.println("strBuf" +strBuf1);//It will Printing rrcshant.
       
       
        //replace(int start, int end, String str)
        // reverse()
        //append(String str)
        //setLength(int newLength)
       
        }
    }