A Tour of Go: https://go-tour-jp.appspot.com/moretypes/18

pic.go

package main

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

func Pic(dx, dy int) [][]uint8 {
    y := make([][]uint8, dy);
    for i := range y {
        y[i] = make([]uint8, dx);
        for j := range y[i] {
            y[i][j] = uint8((i ^ j))
        }
    }

    return y
}

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