Stdle #80 · interfaces · 2026-08-25

What does this Go snippet output?

A past puzzle — fully playable. 4 attempts, hints on wrong guesses.

1package main
2 
3import "fmt"
4 
5type ID int
6 
7func (id ID) String() string { return fmt.Sprintf("#%d", int(id)) }
8 
9func main() {
10	ids := []ID{1, 2}
11	fmt.Println(ids)
12}

Interfaces

What does this Go snippet output?

Answer & explanation