"Coding is today's language of creativity. All our children deserve a chance to become creators instead of consumers of computer science."

Maria Klawe - President of Harvey Mudd College

Rock, Paper, Scissors

Getting Started

After having said hello to the world, we can move on to creating a simple game. We won't be needing any art assets for this one since we'll be making the entire game through code alone. We used C# during the last lesson, and we'll do so again here. This is a simple guide on how you can create a game of "Rock, Paper, Scissors" with randomized elements and variables where you play against the computer. Create a new project once again as you did in the previous lesson.

Let's start by creating a new project. Nothing special needs to be done, just create a new project as you did during the previous lesson. We'll be naming this project RPS, but you can choose whatever name you wish.

Completed Code

Completed Code

Instead of going through the code one line at a time, we're going to show you the full working code right away. Inspect it carefully. Afterwards, we're going to separate it into smaller chunks and go through what is happening in each segment.

using System;

namespace RPS
{
    class Program
    {
        static void Main(string[] args)
        {
            string ans = "";
            int count = 0;
            int count1 = 0;

            Console.WriteLine("Welcome to RPS, time to play");

            while (ans != "NO")
            {
                Console.WriteLine("Make your choice:\n1->ROCK\n2->PAPER\n3->SCISSORS");
                string[] choices = new string[3] { "ROCK", "PAPER", "SCISSORS" };
                Random rnd = new Random();
                int n = rnd.Next(0, 3);
                Console.WriteLine("Enter your choice:");
                string user = Console.ReadLine().ToUpper();
                Console.WriteLine("Computer:" + choices[n]);

                if (user == "ROCK" && choices[n] == "SCISSORS")
                {
                    Console.WriteLine("You win");
                    count += 1;
                }
                else if (user == "ROCK" && choices[n] == "PAPER")
                {
                    Console.WriteLine("Computer wins");
                    count1 += 1;
                }
                else if (user == "PAPER" && choices[n] == "ROCK")
                {
                    Console.WriteLine("You win");
                    count += 1;
                }
                else if (user == "PAPER" && choices[n] == "SCISSORS")
                {
                    Console.WriteLine("Computer wins");
                    count1 += 1;
                }
                else if (user == "SCISSORS" && choices[n] == "ROCK")
                {
                    Console.WriteLine("Computer wins");
                    count1 += 1;
                }
                else if (user == "SCISSORS" && choices[n] == "PAPER")
                {
                    Console.WriteLine("You win");
                    count += 1;
                }
                else
                {
                    Console.WriteLine("Same choices");
                }
                Console.WriteLine("Play again(YES/NO):");
                ans = Console.ReadLine().ToUpper();
                Console.WriteLine("---------------------------------------");
            }
            Console.WriteLine("User wins " + count + " times");
            Console.WriteLine("Computer wins " + count1 + " times");
        }
    }
}

In these segments we set the options that the player can choose. After setting the options, we set the computer's choices as random. If you wanted, you could make the computer always choose a specific option, but where is the fun in that? The final line of code shows what option the computer chooses.

Here we set the rules for the entire game. Which option beats which? We also added a scoring system so that whoever wins a round gets a point that the game will save.

Next, we make the console ask if you wish to replay or not. Choosing "YES" will continue the game, while "NO" ends it. Ending the game will display the result on the screen.

These two lines will display the results of the game - how many wins did each player get?

Quite simple isn't it? But can you manage to beat the computer?


Video tutorial for this lesson

Exercise: The Console

Exercise: The Console

Answer the following question about the material you just learned.