https://tour.golang.org/moretypes/18

exercise-slices.go

package main

import "golang.org/x/tour/pic"

func imageFunc(x, y int) uint8 {
	return uint8(x) ^ uint8(y)	
}

func Pic(dx, dy int) (image [][]uint8) {
	image = make([][]uint8, dy)
	
	for i:= range image {
		image[i] = make([]uint8, dx)
		for j:= range image[i] {
			image[i][j] = imageFunc(i, j)	
		}
	}
	
	return
}

func main() {
	pic.Show(Pic)
}