Visibility

Context

In Go, visibility is determined by capitalization. Identifiers that start with an uppercase letter are exported (visible outside the package). Lowercase identifiers are unexported (private to the package).

Example

Create a package with both exported and unexported identifiers.

Code example

// person.go
package person

type Person struct {
    Name string // exported
    age  int    // unexported
}

func New(name string, age int) Person {
    return Person{Name: name, age: age}
}

func (p Person) GetAge() int { // exported
    return p.age
}

// main.go
package main

import (
    "fmt"
    "person"
)

func main() {
    p := person.New("Alice", 30)
    fmt.Println(p.Name) // ok
    // fmt.Println(p.age) // error: age not exported
    fmt.Println(p.GetAge()) // ok
}

Output

Alice
30

Useful links

• Go spec: Exported identifiers
• Go by Example: Visibility