java append(),insert(),delete(),reverse() method in string buffer

class sbm1
{
	public static void main(String args[])
	{
	StringBuffer buffer = new StringBuffer("Hello");
	System.out.println(buffer.append(" world"));
	
	StringBuffer sb=new StringBuffer("i love my India");
	System.out.println(sb.insert(7,"and like "));
	
	System.out.println(sb.delete(2,6));
	
	System.out.println(sb.reverse());
	
	StringBuffer sb2=new StringBuffer("I hate love story");
	System.out.println(sb2.replace(7,11,"horror"));
	}
}