Tips for getting Sandbox Output

Sandbox Output

Sometimes you may need extra guidance while working through a lesson—especially in Break/Fix lessons. In these cases, you can add print/debug statements to your code to generate output in the Sandbox Output panel.

Output Examples

You can print output to the Sandbox Output panel using standard console/output functions for your language. This is useful for debugging, logging values, or verifying that your patched code is running as expected.

Below are examples of adding output to a simple login function in various languages.

C Output

Use printf (or similar functions) to produce output in the Sandbox Output panel.

#include <stdio.h>

int login(char* username, char* password) {
    printf("Username: %s Password: %s\n", username, password);
    return 0;
}

C# / .NET Output

Use Console.WriteLine to produce output.

public static bool Login(string username, string password) {
    Console.WriteLine($"username is {username}");
    return false;
}

C++ Output

Use std::cout from the iostream library.

#include <iostream>

int login(char* username, char* password) {
    std::cout << "Username: " << username << std::endl;
    return 0;
}

Clojure Output

Use println or printf.

(defn login
  [username password]
  (printf "username is %s%n" username))

Go Output

Import the fmt package and use fmt.Println or fmt.Printf.

package main

import (
    "fmt"
)

func login(username string, password string) (bool, error) {
    fmt.Printf("username is %s\n", username)
    return false, nil
}

Java Output

Use System.out.println or System.out.format.

public static boolean login(String username, String password) {
    System.out.format("username is %s%n", username);
    return false;
}

JavaScript Output

Use console.log.

exports.login = function(username, password) {
  console.log(`username is ${username}`);
};

Kotlin Output

Use println.

fun login(username: String, password: String) {
    println("username is $username")
}

Perl Output

Use print.

sub login {
  my $username = $_[0];
  print "username is $username\n";
}

PHP Output

Use echo.

function login($username, $password) {
  echo 'username is ' . $username . "\n";
}

Python Output

Use print.

def login(username, password):
    print("username is %s" % username)

Ruby Output

Use puts.

def self.login(username, password)
  puts "username is %s" % username
end

Rust Output

Use the println! macro.

fn login(username: &str) {
    println!("username is {username}");
}

Scala Output