Golang : How to shuffle elements in array or slice?
Problem :
You have an array or slice with elements in natural order and you want to shuffle the elements.
Solution :
Use rand.Seed
function to randomize the elements position inside the array or slice.
For example :
package main
import (
"fmt"
"math/rand"
"time"
)
func shuffle(arr []int) {
t := time.Now()
rand.Seed(int64(t.Nanosecond())) // no shuffling without this line
for i := len(arr) - 1; i > 0; i-- {
j := rand.Intn(i)
arr[i], arr[j] = arr[j], arr[i]
}
}
func main() {
//list := rand.Perm(25)
list := []int{1, 2, 3, 4, 5, 6, 7, 8, 9, 10}
fmt.Printf("Original : %v\n", list)
shuffledList := list
shuffle(shuffledList)
fmt.Printf("Shuffled : %v\n", shuffledList)
}
Output :
Original : [1 2 3 4 5 6 7 8 9 10]
Shuffled : [10 3 9 8 2 1 4 6 7 5]
See also : Golang : Generate random elements without repetition or duplicate
By Adam Ng
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