Reverse a string without using string functions [duplicate]

Question

How to write a java program to reverse a string without using string functions?

 String a="Siva";

 for(int i=0;i<=a.length()-1;i++)
 {
     System.out.print(a.charAt(i));
 }
     System.out.println("");

 for(int i = a.length() - 1; i >= 0; --i)
 {
     System.out.print(a.charAt(i)); 
 }

here charAt() and a.length() are string functions

Answer 1

This will help

public class StringReverse {

   public static void main(String[] args){
    String str = "Reverse";
    StringBuilder sb = new StringBuilder(str);
    str = sb.reverse().toString();
    System.out.println("ReverseString : "+str);
  }

}

There is no usage of String methods