Building a Simple Rock, Paper, Scissors Game in Go

Rock, Paper, Scissors is a classic game that has been played for generations. In this blog, we will walk through how to build a simple command-line version of the game in Go.

Prerequisites

Before we dive into the code, ensure you have the Go programming language installed on your system. You can download it from Go's official website.

Understanding the Code

Let's break down the code and understand its structure.

Importing Necessary Packages

import (
    "fmt"
    "math/rand"
)

Here, we import the fmt package for handling input and output operations and math/rand to generate random choices for the computer.

Defining Variables

playerScore := 0
computerScore := 0
option := []string{"rock", "paper", "scissors"}
var playerChoice string

• playerScore and computerScore are initialized to keep track of the game scores.
• option is a slice containing the three possible choices: rock, paper, and scissors.
• playerChoice is a variable that stores the player's choice.

Running the Game Loop

for {
    computerChoice := option[rand.Intn(len(option))]

This loop runs indefinitely, allowing players to continue playing until they manually stop the program.

• rand.Intn(len(option)) generates a random index to select the computer’s choice.

Taking Player Input

fmt.Print("choose an option, rock, paper and scissors: ")
fmt.Scan(&playerChoice)
fmt.Printf("Computer Choice:  %v \n", computerChoice)
fmt.Printf("player Choice:  %v  \n", playerChoice)

• fmt.Print() prompts the player to enter a choice.
• fmt.Scan(&playerChoice) captures the user's input.
• The selected choices for both the player and the computer are displayed.

Determining the Winner

if playerChoice == computerChoice {
    fmt.Println("no winner(tie)")
    fmt.Printf("game score Player %v, computer %v \n", playerScore, computerScore)

If both choices are the same, it results in a tie, and scores remain unchanged.

Player Wins Condition

} else if playerChoice == "rock" && computerChoice == "scissors" ||
          playerChoice == "paper" && computerChoice == "rock" ||
          playerChoice == "scissors" && computerChoice == "paper" {
    fmt.Println("player wins")
    playerScore++

The player wins if:

• Rock beats scissors
• Paper beats rock
• Scissors beat paper

The player’s score is incremented accordingly.

Computer Wins Condition

} else {
    fmt.Println("computer Wins")
    computerScore++
    fmt.Printf("game score Player %v, computer %v \n", playerScore, computerScore)
}

If none of the conditions above are met, the computer wins, and its score increases.

Running the Game

Save the code in a file, say main.go, and run it using:

go run main.go

You can play multiple rounds until you choose to stop the game manually (Ctrl + C).

Fixing an Error in the Code

There's a small typo in the condition checking for the player's win. The condition:

playerChoice == "scissor" && computerChoice == "paper"

should be corrected to:

playerChoice == "scissors" && computerChoice == "paper"

Since "scissors" is the correct string defined in the option slice, fixing this ensures the program works correctly.

Conclusion

This simple Rock, Paper, Scissors game demonstrates basic Go programming concepts such as loops, conditionals, and user input handling. You can enhance the game by adding features like a limit on rounds, an option to exit, or even integrating a graphical interface.

the full code also on my github here

Try modifying the code and share your improvements! 🚀