Program for subString()

import java.util.Scanner;
public class Strings_SubString 
{
 public static String subString(String s , int start ,int end)
 {
 char[] ch = s.toCharArray();
 String res = "";
 for (int i = start; i < end; i++) 
 {
 res = res + ch[i];
 }
 return res;
 }
 public static void main(String[] args) 
 {
 Scanner sc = new Scanner(System.in);
 System.out.println("Enter the String :- ");
 String s1 = sc.nextLine();
 System.out.println("Enter the starting index :- ");
 int a = sc.nextInt();
 System.out.println("Enter the ending index :- ");
 int b = sc.nextInt();
 System.out.println(subString(s1,a,b));
 sc.close();
}
}