Go - call me - Functions - Using pointers with functions

Head First Go
楽天ブックス 紀伊國屋書店

開発環境

• macOS Mojave - Apple (OS)
• Emacs (Text Editor)
• Windows 10 Pro (OS)
• Visual Studio Code (Text Editor)
• Go (プログラミング言語)

Head First Go (Jay McGavren(著)、O'Reilly Media)のChapter 3(call me - Functions)、Exercise(109)の解答を求めてみる。

コード

sample4_test.go

package main

import "testing"

func TestNegate(t *testing.T) {
 truth := true
 negate(&truth)
 if truth != false {
  t.Errorf("truth: %v", truth)
 }
 lies := false
 negate(&lies)
 if lies != true {
  t.Errorf("truth: %v", lies)
 }
}

sample4.go

package main

func negate(myBooleanPointer *bool) {
 *myBooleanPointer = !*myBooleanPointer
}
func main() {}

入出力結果(Bash、cmd.exe(コマンドプロンプト)、Terminal)

$ go test
# _/.../Head_First_Go/ch3/sample4 [_/.../Head_First_Go/ch3/sample4.test]
./sample4_test.go:7:2: undefined: negate
./sample4_test.go:12:2: undefined: negate
FAIL _/.../Head_First_Go/ch3/sample4 [build failed]
$ go test
PASS
ok   _/.../Head_First_Go/ch3/sample4 0.005s
$