Golang : Roll the dice example
Just a simple example on how to simulate dice rolling. Useful in situation where you need to use random single digit number to ensure different results very time.
UPDATE: The previous code used dice[rand.Intn(len(dice)-1)]
, which caused the dice to never reach the position 6
and also run rand.Seed(time.Now().UnixNano())
multiple times - which is an unnecessary overhead. The code below has been updated to correct the bug and rand.Seed()
function only executes once throughout the duration of this program. Thanks to Patrik Lundin for pointing this out.
Here you go!
package main
import (
"fmt"
"math/rand"
"sync"
"time"
)
var onlyOnce sync.Once
// prepare the dice
var dice = []int{1, 2, 3, 4, 5, 6}
func rollDice() int {
onlyOnce.Do(func() {
rand.Seed(time.Now().UnixNano()) // only run once
})
return dice[rand.Intn(len(dice))]
}
func main() {
dice1 := rollDice()
dice2 := rollDice()
dice3 := rollDice()
fmt.Println("Dice 1: ", dice1)
fmt.Println("Dice 2: ", dice2)
fmt.Println("Dice 3: ", dice3)
}
Sample output:
Dice 1: 6
Dice 2: 2
Dice 3: 2
Dice 1: 5
Dice 2: 1
Dice 3: 3
Happy coding!
Reference:
https://www.socketloop.com/tutorials/golang-how-to-run-your-code-only-once-with-sync-once-object
See also : Golang : Scramble and unscramble text message by randomly replacing words
By Adam Ng
IF you gain some knowledge or the information here solved your programming problem. Please consider donating to the less fortunate or some charities that you like. Apart from donation, planting trees, volunteering or reducing your carbon footprint will be great too.
Advertisement
Tutorials
+4.6k Golang : What is StructTag and how to get StructTag's value?
+8.1k Golang : Play .WAV file from command line
+4.9k Golang : Find change in a combination of coins example
+17.8k Golang : How to make function callback or pass value from function as parameter?
+8.9k Golang : Get current, epoch time and display by year, month and day
+11.4k Elastic Search : Return all records (higher than default 10)
+11.6k Golang : Transform comma separated string to slice example
+14.9k Golang : convert string or integer to big.Int type
+4.3k Golang : How to deal with configuration data?
+15.1k Golang : Test floating point numbers not-a-number and infinite example
+5.5k Unix/Linux : Use netstat to find out IP addresses served by your website server
+7.8k Golang : Build and compile multiple source files