Invoke golang struct function gives “cannot refer to unexported field or method”
I have a golang structure something like this:
type MyStruct struct {
Id string
}
and function:
func (m *MyStruct) id() {
// doing something with id here
}
Also i have another structure like this:
type MyStruct2 struct {
m *MyStruct
}
Now i have a function:
func foo(str *MyStruct2) {
str.m.id()
}
But i'm getting error in compile time:
str.m.id undefined (cannot refer to unexported field or method mypackage.(*MyStruct)."".id
How can i call this function correctly?
Thank you
Answers
From http://golang.org/ref/spec#Exported_identifiers:
An identifier may be exported to permit access to it from another package. An identifier is exported if both:
- the first character of the identifier's name is a Unicode upper case letter (Unicode class "Lu"); and
- the identifier is declared in the package block or it is a field name or method name.
So basically only functions / variables starting with a capital letter would be usable outside the package.
Example:
type MyStruct struct {
id string
}
func (m *MyStruct) Id() {
// doing something with id here
}
//then
func foo(str *MyStruct2) {
str.m.Id()
}