Golang : Combine slices but preserve order example

In the previous tutorial on how to join arrays in Golang, we use the append function to join arrays/slices. However, there are times when we need to pack or join few arrays/slices into a single array, but preserving their order and to transmit the single array over the network or serialized to disk before unpacking the single array back into the original arrays later on.

To use append function for this situation is unwise. Below is a simple example on how to pack the arrays/slices into a single 2-dimensional array and unpack it.

 package main

 import (
 "fmt"
 )

 func main() {
 a := []int{1, 2, 3}
 b := []int{4, 5, 6}
 c := []int{7, 8, 9}
 d := [][]int{a, b}

 // two slices in one slice
 fmt.Println(d)

 // two distinct slices
 fmt.Println(a, b)

 // to add c, need to use new variable e
 e := [][]int{a, b, c}
 fmt.Println(e)

 // change order just for fun
 f := [][]int{c, b, a}
 fmt.Println(f)

 // unpack
 fmt.Println("c : ", f[0])
 fmt.Println("b : ", f[1])
 fmt.Println("a : ", f[2])

 }

Output:

[[1 2 3] [4 5 6]]

[1 2 3] [4 5 6]

[[1 2 3] [4 5 6] [7 8 9]]

[[7 8 9] [4 5 6] [1 2 3]]

c : [7 8 9]

b : [4 5 6]

a : [1 2 3]

Happy coding!