Go - Variables(creating, scope, var, const)

Introducing Go

開発環境

• OS X El Capitan - Apple (OS)
• Emacs (Text Editor)
• Go (version go1.5.2 darwin/amd64) (プログラミング言語)

Introducing Go (Caleb Doxsey (著)、O'Reilly Media)のChapter 3.(Variables)、Exercises 1-6.(No. 480)を取り組んでみる。

Exercises 1-6.(No. 480)

コード(Emacs)

package main

import "fmt"

func fahrenheitToCelsius(x float64) float64 {
 return (x - 32) * 5 / 9
}
func feetToMeters(feet float64) float64 {
 return feet * 0.3048
}
func main() {
 fmt.Println("1.")
 a := 10
 var b int
 b = 10
 fmt.Println(a)
 fmt.Println(b)

 fmt.Println("2.")
 x := 5
 x += 1
 fmt.Println(x == 6)

 fmt.Println("3. block scope")
 fmt.Println(x)
 {
  x := "block"
  fmt.Println(x)
 }
 fmt.Println(x)

 fmt.Println("4.")
 var v1 int = 1
 const v2 int = 1

 v1 = 10
 // v2 = 10
 fmt.Println(v1)
 fmt.Println(v2)

 fmt.Println("5.")
 var f float64 = 0
 for f <= 100 {
  fmt.Println(fahrenheitToCelsius(f))
  f += 10
 }
 fmt.Println("6.")
 f = 0
 for f <= 100 {
  fmt.Println(feetToMeters(f))
  f += 10
 }
}

入出力結果(Terminal)

$ go run main.go
1.
10
10
2.
true
3. block scope
6
block
6
4.
10
1
5.
-17.77777777777778
-12.222222222222221
-6.666666666666667
-1.1111111111111112
4.444444444444445
10
15.555555555555555
21.11111111111111
26.666666666666668
32.22222222222222
37.77777777777778
6.
0
3.048
6.096
9.144
12.192
15.24
18.288
21.336000000000002
24.384
27.432000000000002
30.48
$