Home > Article > Backend Development > How to provide a value to an imported embedded structure literal?
This is a newbie:) I can not understand
When I do this in a file:
scratch.go
package main import "fmt" type foo struct { field1 string field2 string } type bar struct { foo field3 string field4 string } func main() { foobar := bar{ foo{ "apples", "banana", }, "spam", "eggs", } fmt.printf("%#v\n", foobar) }
It works But when I have 3 files like this
rootproject ├── magazine │ ├── address.go │ └── employee.go └── main.go
magazine/address.go
package magazine type address struct { street string city string state string postalcode string }
magazine/employee.go
package magazine type employee struct { name string salary float64 address }
and
main.go
package main import ( "fmt" "magazine" ) func main() { employee := magazine.employee{ name: "pogi", salary: 69420, magazine.address{ street: "23 pukinginamo st.", city: "bactol city", state: "betlog", postalcode: "23432", }, } fmt.printf("%#v\n", employee) }
mistake:(
mixture of field:value and value elements in struct literal
I don't understand, what did I do wrong? I think if the structure is nested, it is said to be embedded in the outer structure and I can access the inner structure's fields from the outer structure. This is the case with my first example (single file), but when I do this in a package. Is there any difference?
I think if the structure is nested, it is said to be embedded in the outer structure and I can access the fields of the inner structure from the outer structure .
Yes, you can directly access members of an embedded field, but this is done using compound literals. If you look at the rules for structured literals, you'll find the following:
If any element has a key, then every element must have a key.
This rule applies regardless of whether the field is embedded or not.
To fix the error, you can delete other keys:
func main() { employee := magazine.employee{ "pogi", 69420, magazine.address{ street: "23 pukinginamo st.", city: "bactol city", state: "betlog", postalcode: "23432", }, } fmt.printf("%#v\n", employee) }
Or you can specify all keys:
func main() { employee := magazine.Employee{ Name: "pogi", Salary: 69420, Address: magazine.Address{ Street: "23 pukinginamo st.", City: "bactol city", State: "betlog", PostalCode: "23432", }, } fmt.Printf("%#v\n", employee) }
Note that for embedded fields, you can reference the embedded field using the unqualified name of the type.
https://www.php.cn/link/2eeb0ca3f02a275d5179f3b6d9e86e7d:
Fields declared with a type but without an explicit field name are called embedded fields. Embedded fields must be specified as type names t
or pointers to non-interface type names *t
, and t
itself may not be a pointer type. Unqualified type names act as field names.
The above is the detailed content of How to provide a value to an imported embedded structure literal?. For more information, please follow other related articles on the PHP Chinese website!