[GO]全局变量

package main

import "fmt"

func test01()  {
    fmt.Println("test a = ", a)
}

//a := 10 <--- 注意：这种方式是不正确的
//函数外部的变量就是全局变量
var a int

func main()  {
    a =
    fmt.Println("a = ", a)
    test01()
}

得到哪下结果

GOROOT=C:\Go #gosetup
GOPATH=E:\go\develop #gosetup
C:\Go\bin\go.exe build -i -o C:\Users\baylor\AppData\Local\Temp\___go_build__go.exe E:/awesomeProject01/全局变量.go #gosetup
"C:\Program Files\JetBrains\GoLand 2018.1.5\bin\runnerw.exe" C:\Users\baylor\AppData\Local\Temp\___go_build__go.exe #gosetup
a =
test a =