Golang Program to Create a Class and Compute the Area and Perimeter of a Circle

To compute the area and perimeter of a circle, we can take following steps −

• Define a struct with circle properties such as radius.
• Define a method to calculate the area of the circle.
• Define a method to calculate the perimeter of the circle.
• In the main method, take the user's input for circle's radius.
• Instantiate the circle with the radius.
• Print the area of the circle.
• Print the perimeter of the circle.

Example

 Live Demo

package main
import (
   "fmt"
   "math"
)
type Circle struct {
   radius float64
}
func (r *Circle)Area() float64{
   return math.Pi * r.radius * r.radius
}
func (r *Circle)Perimeter() float64{
   return 2 * math.Pi * r.radius
}
func main(){
   var radius float64
   fmt.Printf("Enter radius of the circle: ")
   fmt.Scanf("%f", &radius)
   c := Circle{radius: radius}
   fmt.Printf("Area of the circle is: %.2f\n", c.Area())
   fmt.Printf("Perimeter of the circle is: %.2f\n", c.Perimeter())
}

Output

Enter radius of the circle: 7
Area of the circle is: 153.94
Perimeter of the circle is: 43.98