import java.io.*;

public class stringBuffer{
	public static void main(String[] args) throws Exception{
		BufferedReader in = new BufferedReader(new InputStreamReader(System.in));
		String str;
		try{
			System.out.print("Enter your name: ");
			str = in.readLine();
			str += ", This is the example of SringBuffer class and it's functions.";

			//Create a object of StringBuffer class
			StringBuffer strbuf = new StringBuffer();
			System.out.print(strbuf.length());
			strbuf.append(str);
			System.out.println(strbuf);
			strbuf.delete(0,str.length());
			
			//append()
			strbuf.append("Hello");
			strbuf.append("World");							//print HelloWorld
			System.out.println(strbuf);
			
			//insert()
			strbuf.insert(5,"_Java ");						//print Hello_Java World
			System.out.println(strbuf);
			
			//reverse()
			strbuf.reverse();
			System.out.print("Reversed string : ");
			System.out.println(strbuf);						//print dlroW avaJ_olleH
			strbuf.reverse();
			System.out.println(strbuf);						//print Hello_Java World
			
			//setCharAt()
			strbuf.setCharAt(5,' ');
			System.out.println(strbuf);						//prit Hello Java World
			
			//charAt()
			System.out.print("Character at 6th position : ");
			System.out.println(strbuf.charAt(6));			//print J
	
			//substring()
			System.out.print("Substring from position 3 to 6 : ");
			System.out.println(strbuf.substring(3,7));		//print lo J
						
			//deleteCharAt()
			strbuf.deleteCharAt(3);
			System.out.println(strbuf);						//print Helo java World
			
			//capacity()
			System.out.print("Capacity of StringBuffer object : ");
			System.out.println(strbuf.capacity());			//print 21
			
			//delete() and length()
			strbuf.delete(6,strbuf.length());				
			System.out.println(strbuf);						//no anything
		}
		catch(StringIndexOutOfBoundsException e){
			System.out.println(e.getMessage());
		}
	}
}