w3resource

Java Exercises: Reverse a string

Java Basic: Exercise-37 with Solution

Write a Java program to reverse a string.

Test Data:
Input a string: The quick brown fox

Pictorial Presentation: Reverse a string

Java: Reverse a string

Sample Solution:

Java Code:

import java.util.Scanner;
public class Exercise37 {
     public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        System.out.print("Input a string: ");
        char[] letters = scanner.nextLine().toCharArray();
        System.out.print("Reverse string: ");
        for (int i = letters.length - 1; i >= 0; i--) {
            System.out.print(letters[i]);
        }
        System.out.print("\n");
    }
}

Sample Output:

Input a string: The quick brown fox                      
Reverse string: xof nworb kciuq ehT

Flowchart:

Flowchart: Java exercises: Reverse a string

Java Code Editor:

Contribute your code and comments through Disqus.

Previous: Write a Java program to compute the distance between two points on the surface of earth.
Next: Write a Java program to count the letters, spaces, numbers and other characters of an input string.

What is the difficulty level of this exercise?



Java: Tips of the Day

Execution of console commands:

Java allows you to execute console commands directly from code using a class Runtime. It is very important not to forget about exception handling.

For example, let's try to open a PDF file through a Java terminal:

import java.io.BufferedReader;
import java.io.InputStream;
import java.io.InputStreamReader;
  
public class ShellCommandExec {
  
  public static void main(String[] args) {
    String gnomeOpenCommand = "gnome-open //home//user//Documents//MyDoc.pdf";
  
    try {
      Runtime rt = Runtime.getRuntime();
      Process processObj = rt.exec(gnomeOpenCommand);
  
      InputStream stdin = processObj.getErrorStream();
      InputStreamReader isr = new InputStreamReader(stdin);
      BufferedReader br = new BufferedReader(isr);
  
      String myoutput = "";
  
      while ((myoutput=br.readLine()) != null) {
        myoutput = myoutput+"\n";
      }
      System.out.println(myoutput);
    }
    catch (Exception e) {
      e.printStackTrace();
    }
  }
}