为什么我的包裹中的功能无法正常工作

Question

I have put a small code file in $GOPATH which is ~/go/src. Here I have made a folder mysrc and there I have kept a file mytest.go, which is as follows:

package mytest
import ("fmt")
func myfn(){
  fmt.Println("My own fn")
}

I try to import above code with following file:

package main
import ("mysrc")
main(){
    myfn()
}

When I try to run above file, I get error:

# command-line-arguments
./useMyfn.go:3:1: syntax error: non-declaration statement outside function body

Where is the problem and how can it be solved? Thanks for your help.

Edit: I corrected the main fn to func main() but now the errors are:

# command-line-arguments
./useMyfn.go:2:9: imported and not used: "mysrc" as mytest
./useMyfn.go:4:2: undefined: myfn

Answer 1

You need to do few things

1. I suggest to use a package name that the name is same with the folder name.
2. The myfn() function need to be exported. How to do it: simply set the first character of the function name to uppercase.

package mysrc // <-- 1

import (
    "fmt"
)

func Myfn() { // <-- 2
    fmt.Println("My own fn")
}

1. The func keyword is required before main() statement.

2. To access a function from other package, you need to write down the package name before the function name. In this context it'll be mysrc.Myfn().

package main

import (
    "mysrc"
)

func main() { // <-- 3
    mysrc.Myfn() // <-- 4
}