Interface is a protocol – a contract. It only describes the expected behavior, It is an abstract type.
Use Case 1:
Program to print value through interface.
package main
import “fmt”
funcmyfunc(a interface{}) {
v := a.(string)
fmt.Println(“value :”, v)
}
funcmain() {
var v interface {
} = “Prwatech”
myfunc(v)
}
Output :
Use Case 2:
Program for geometric shapes.
package main
import (
“fmt”
“math”
)
type geometry interface {
area() float64
perim() float64
}
type rect struct {
width, height float64
}
type circle struct {
radius float64
}
func (r rect) area() float64 {
return r.width * r.height
}
func (r rect) perim() float64 {
return 2*r.width + 2*r.height
}
func (c circle) area() float64 {
return math.Pi * c.radius * c.radius
}
func (c circle) perim() float64 {
return 2 * math.Pi * c.radius
}
funcmeasure(g geometry) {
fmt.Println(g)
fmt.Println(g.area())
fmt.Println(g.perim())
}
funcmain() {
r := rect{width: 3, height: 4}
c := circle{radius: 5}
measure(r)
measure(c)
}
Output:
Use Case 3:
package main
import (
“fmt”
)
funcmyFunc(a interface{}) {
fmt.Println(a)
}
funcmain() {
var my_age int
my_age = 25
myFunc(my_age)
}
Output :