Go lang中的Getter和Setter约定

Question

Case A Not following the Getter & Setter convention

human/human.go

package human

type Human interface {
    GetName() string
    SetName(name string)
}

type Person struct {
    Name string
}

func (p Person) GetName() string {
    return p.Name
}

func (p *Person) SetName(name string) {
    p.Name = name
}

main/main.go

package main

func main() {
    john := Person{Name:"john"} // Uppercase Fields are visible
    fmt.Println(john)
}

---

Case B Following getter and setter convention

package human

type Human interface {
    Name() string
    SetName(name string)
}

type Person struct {
    name string
}

func (p Person) Name() string {
    return p.name
}

func (p *Person) SetName(name string) {
    p.name = name
}

main/main.go

package main

func main() {
    john := Person(name: "John") // lowercase name is not visible outside the package
}

The problem with following convention is that I can't instantiate the struct while providing its field names. I'd like to use the convention but I am stuck with the private access.

Answer 1

When instantiating a structure (or object, in object oriented languages), you should not specify the value of private fields anyway. It can make sense, however, to provide data that may end up in private fields, or be treated in a completely different manner. In this case, OOP warrants the use of a constructor, and the Go convention is a to provide a fuction called New[YourStructure].

func NewPerson(name string) Person {
    return Person{name: name}
}

In this trivial example, the name is simply copied to the private field, but in a more complex example, other operations could take place (e.g. checking that the name is valid, or looking up the name and taking action depending on the result…).