Challenge 3 — Solution

Task: Given colours := []string{"red", "green", "blue", "yellow"},
use for...range with the blank identifier _ to print just the
values, one per line, with no index shown.

package main

import "fmt"

func main() {
	colours := []string{"red", "green", "blue", "yellow"}

	for _, colour := range colours {
		fmt.Println(colour)
	}
}


Expected output:

red
green
blue
yellow

Notes:
- range always returns both an index and a value for a slice; _ is
  used here to explicitly discard the index since it's never used.
- Without the _, writing "for index, colour := range colours" but
  then never using index would be a compile error — Go requires
  every declared variable to be used, and _ is the designated way to
  opt out of that requirement for one value.
- []string{...} is a slice literal — Go's everyday equivalent of a
  JavaScript array — created and filled with values in one line.