When we have complex groups of fields in our structs, they can be combined into their own struct! For example, in the Employee struct, we have two separate fields for the first and last name of the employee. We can combine those two strings into their own struct called Name:

type Name struct{
  firstName string
  lastName string
}

type Employee struct{
  name Name
  age int
  title string
}

We create an instance of Employee like so:

carl := Employee{Name{“Carl”, “Carlson”}, 32, “Engineer”}

To access the fields of the nested struct (Name in this case), we chain together the field accesses like so:

fmt.Println(carl.name.lastName) // Output will be “Carlson”

We can also define the employee struct with the Name struct anonymously like so:

type Employee struct{
  Name
  age int
  title string
}

Notice how the Name file has no associated variable name with it.

Composing a struct in this way allows us to access the firstName and lastName fields directly from the Employee struct.

carl := Employee{Name{“Carl”, “Carlson”}, 32, “Engineer”}

fmt.Println(carl.firstName) // Output will be “Carl”
fmt.Println(carl.lastName) // Output will be “Carlson”

We, of course, cannot have two anonymous fields of the same type (i.e., two Name fields) as that would make it impossible to tell which field is being accessed (which firstName if two anonymous Name fields).

An anonymous field is used to field access easier and leads to cleaner code.

We now have the ability to organize struct information inside of existing structs! Let’s get some hands-on practice.