Java Append and Insert Program

import java.lang.*;

public class AppendInsert{
      public static void main(String[] args) {
          System.out.println("StringBuffer insert and append example!");
          StringBuffer sb = new StringBuffer(0);
          //First position
          System.out.println(sb.insert(0, "Raj"));
          int len = sb.length();
         //last position
         System.out.println(sb.insert(len, "Deepak"));
         //Six position
         System.out.println(sb.insert(6, "kumar"));
         //Always last
         System.out.println(sb.append("Mohit"));
     }
}