Write a java program to Reverse SubString

Given a string, startIndex and length, write a program to extract the substring from right to left. Assume the last character has an index of 0.

The 1^st argument corresponds to the string, the second argument corresponds to the startIndex and the third argument corresponds to the length.

Input and Output Format

• The first line of the input consists of a string.
• The second line of the input consists of an integer that corresponds to the startIndex.
• The third line of the input consists of an integer that corresponds to the length of the substring.

Sample Input:

rajasthan

2

3

Sample Output:

hts

Program to Reverse SubString in Java

Following are the steps to reverse substring:

• Input string, start index, and length of the string from the user.
• Pass them to retrieveString() method.
• Inside the method, Create an instance of string buffer with the input string. Call the reverse() method to reverse the input string.
• Now pass the string, start index+length to the substring() method and get the output string.
• At last, return the resultant string to the user.

import java.util.Scanner;

public class Main {
  public static void main(String[] args) {
    Scanner sc = new Scanner(System.in);

    String input1 = sc.nextLine();
    int input2 = sc.nextInt();
    int input3 = sc.nextInt();
    System.out.println(retrieveString(input1, input2, input3));
  }

  public static String retrieveString(String input1, int input2, int input3) {
    StringBuffer sb = new StringBuffer(input1);
    sb.reverse();
    String output = sb.substring(input2, input2 + input3);
    return output;
  }
}

Output

Thus, in this way, we learn how to find the reverse of a substring in Java.