In Go structure, the working of promoted methods is just like Promoted Fields. We use this concept in the nested structure where a structure is a field in another structure, simply by just adding the name of the structure into another structure and it behaves like the Anonymous Field to the nested structure. And the methods of that structure (other than nested structure) are the part of the nested structure, such type of methods are known as Promoted Methods. Or in other words, prompted methods are those methods which are implemented by the child structure, and is accessible by the parent structure.
Important Points:
- If the child and the parent structure contain a method that has the same name but different type of receiver, then both the methods are available in the parent structure as shown in Example 2. Here both child and parent structure contain methods of the same names.
- If child structure contains two methods with the same name and same receiver, then these methods are not promoted in the parent structure and if you try to do, then the compiler will give an error.
Example 1:
package main
import "fmt"
type details struct {
name string
age int
gender string
psalary int
}
type employee struct {
post string
eid int
details
}
func (d details) promotmethod(tsalary int ) int {
return d.psalary * tsalary
}
func main() {
values := employee{
post: "HR" ,
eid: 4567,
details: details{
name: "Sumit" ,
age: 28,
gender: "Male" ,
psalary: 890,
},
}
fmt.Println( "Name: " , values.name)
fmt.Println( "Age: " , values.age)
fmt.Println( "Gender: " , values.gender)
fmt.Println( "Per day salary: " , values.psalary)
fmt.Println( "Total Salary: " , values.promotmethod(30))
fmt.Println( "Post: " , values.post)
fmt.Println( "Employee id: " , values.eid)
}
|
Output:
Name: Sumit
Age: 28
Gender: Male
Per day salary: 890
Total Salary: 26700
Post: HR
Employee id: 4567
Example 2:
package main
import "fmt"
type details struct {
name string
age int
gender string
psalary int
}
func (e employee) promotmethod(tarticle int ) int {
return e.particle * tarticle
}
type employee struct {
post string
particle int
eid int
details
}
func (d details) promotmethod(tsalary int ) int {
return d.psalary * tsalary
}
func main() {
values := employee{
post: "HR" ,
eid: 4567,
particle: 5,
details: details{
name: "Sumit" ,
age: 28,
gender: "Male" ,
psalary: 890,
},
}
fmt.Println( "Name: " , values.name)
fmt.Println( "Age: " , values.age)
fmt.Println( "Gender: " , values.gender)
fmt.Println( "Per day salary: " , values.psalary)
fmt.Println( "Total Salary: " , values.promotmethod(30))
fmt.Println( "Post: " , values.post)
fmt.Println( "Employee id: " , values.eid)
fmt.Println( "Total Articles: " , values.promotmethod(30))
}
|
Output:
Name: Sumit
Age: 28
Gender: Male
Per day salary: 890
Total Salary: 150
Post: HR
Employee id: 4567
Total Articles: 150