type InterfaceName interface {
       method1(arg1 type1, arg2 type2) returnType1
       method2(arg3 type3) returnType2
       // ...
   }
   
   type TypeName struct {
       // fields
   }

   func (t TypeName) method1(arg1 type1, arg2 type2) returnType1 {
       // implementation
   }

   func (t TypeName) method2(arg3 type3) returnType2 {
       // implementation
   }

				
			

				
					  package main

   import "fmt"

   type MyString string

   type Rectangular struct {
       width  float64
       height float64
   }

   func emptyInterface(i interface{}) {
       fmt.Printf("Value given to emptyInterface function is of type '%T' with value %v\n", i, i)
   }

   func main() {
       myString := MyString("My name is MD ABU SALMAN HOSSAIN")
       rectangular := Rectangular{5.2, 7}


       emptyInterface(myString)
       emptyInterface(rectangular)
   }

				
			

				
					  package main

   import (
       "fmt"
       "math"
   )

   type Shape interface {
       Area() float64
   }

   type Object interface {
       Volume() float64
   }

   type Cylinder struct {
       radius float64
       height float64
   }

   func (c Cylinder) Area() float64 {
       return 2 * math.Pi * c.radius * (c.radius + c.height)
   }

   func (c Cylinder) Volume() float64 {
       return math.Pi * c.radius * c.radius * c.height
   }

   func main() {
       var shape Shape = Cylinder{3.2, 4.3}
       cylinder := shape.(Cylinder)
       fmt.Println("Area of shape of interface type Shape is ", cylinder.Area())
       fmt.Println("Volume of object of interface type Object is ", cylinder.Volume())
   }