// Chapter 27 example: a function that returns nil for "no answer", and a
// caller that checks for it.
// Run with: go run exercises/27/06-nil-check.go

package main

import "fmt"

type character struct {
	name string
	hp   int
}

// stronger returns whichever character has more hp, or nil for a tie.
func stronger(a *character, b *character) *character {
	if a.hp > b.hp {
		return a
	}
	if b.hp > a.hp {
		return b
	}
	return nil
}

func announce(winner *character) {
	if winner == nil {
		fmt.Println("It is a tie.")
		return
	}
	fmt.Println(winner.name, "is stronger.")
}

func main() {
	ada := &character{name: "Ada", hp: 100}
	ben := &character{name: "Ben", hp: 80}
	cara := &character{name: "Cara", hp: 100}

	announce(stronger(ada, ben))
	announce(stronger(ada, cara))
}