A struct is a user-defined type that contains named fields.

// Anonymous struct literal (declaration + initialization).
p := struct {
	Name string
	Age  int
}{
	Name: "John",
	Age:  36,
}

Accessing struct pointers

If you make a pointer to a struct, you can access its fields in two ways:

// Named struct (declaration).
type Person struct {
	Name string
	Age  int
}

func main() {
	p := &Person{"Joe", 42}
	fmt.Println((*p).Name) // explicit dereferencing; it's cumbersome
	fmt.Println(p.Name)    // implicit dereferencing done by the language
}

Populating structs

Rather than populating a struct by passing a pointer to it into a function, have the function instantiate and return the struct.

Don’t do this:

func MakePerson(p *Person) error {
    p.Name = "John"
    p.Age = 36
    return nil
}

Do this:

func MakePerson() (*Person, error) {
    p := Person{
        Name: "John",
        Age: 36,
    }
    return &p, nil
}

One exception is when a function expects an interface:

p := struct {
	Name string
	Age  int
}{}

err := json.Unmarshal([]byte(`{"Name": "John", "Age": 36}`), &p)