Golang : Create and shuffle deck of cards example

Problem:

You want to create a computer game like Strip Poker or you simply want to create a program that uses a deck of cards for studying gambling or probability. Instead of hand coding each card with text string into a map, you want to create the cards on the fly into a slice and want to shuffle the cards as well. How to do that?

Solution:

Create two arrays such as

 var suit = [4]string{"Hearts", "Diamonds", "Clubs", "Spades"}

and

 var face = [13]string{"Ace", "Deuce", "Three", "Four", "Five", "Six", "Seven", "Eight", "Nine", "Ten", "Jack", "Queen", "King"}

then combine the elements with for loops to create the initial deck of cards. You can create a separate function to shuffle the cards afterward.

Here you go!

 package main

 import (
 "fmt"
 "math/rand"
 "time"
 )

 // let just stick to arrays instead of slice
 // because 4 x 13 is pretty standard for most decks....unless you want to include jokers.

 var suit = [4]string{"Hearts", "Diamonds", "Clubs", "Spades"}

 var face = [13]string{"Ace", "Deuce", "Three", "Four", "Five", "Six", "Seven", "Eight", "Nine", "Ten", "Jack", "Queen", "King"}

 const rows = 13
 const columns = 4
 const total = rows * columns

 // shuffle deck of cards
 func shuffleDeck(workDeck []string) []string {

 shuffled := make([]string, len(workDeck))

 rand.Seed(time.Now().UTC().UnixNano())
 perm := rand.Perm(len(workDeck))

 for i, v := range perm {
 shuffled[v] = workDeck[i]
 }

 return shuffled
 }

 func main() {

 var initDeck []string

 //initialize or populate our initial deck of cards
 //in sorted form
 for r := 0; r <= rows-1; r++ {
 for c := 0; c <= columns-1; c++ {
 tmp := face[r] + " of " + suit[c]
 initDeck = append(initDeck, tmp)

 }
 }

 // our new deck of cards is sorted !
 for k, v := range initDeck {
 fmt.Printf("%d %s\n", k, v)
 }

 fmt.Println("-----shuffling deck------")
 shuffledDeck := shuffleDeck(initDeck)

 // our new deck of cards is now shuffled !
 for k, v := range shuffledDeck {
 fmt.Printf("%d %s\n", k, v)
 }

 }

Output:

0 Ace of Hearts

1 Ace of Diamonds

2 Ace of Clubs

3 Ace of Spades

...

50 King of Clubs

51 King of Spades

-----shuffling deck------

0 Ace of Spades

1 Deuce of Clubs

2 Seven of Diamonds

3 Deuce of Diamonds

4 Queen of Clubs

5 Ten of Diamonds

6 Nine of Hearts

7 Deuce of Spades

...

49 Jack of Hearts

50 Ten of Spades

51 Six of Diamonds

Happy coding!

References:

https://en.wikipedia.org/wiki/Strip_poker (NSFW)

https://www.socketloop.com/tutorials/golang-shuffle-strings-array