Go Program to Calculate the Area of a Circle

1. Introduction

In this guide, we'll explore the process of developing a Go program that calculates the area of a circle given its radius.

2. Program Overview

Our Go program is structured to:

1. Request the user to input the radius of the circle.

2. Calculate the area using the formula π * radius^2.

3. Present the computed area to the user.

3. Code Program

// The program begins with the declaration of the main package.
package main

// We enlist the fmt package to handle input and output tasks and the math package for mathematical constants and operations.
import (
    "fmt"
    "math"
)

// Function to determine the area of the circle.
func circleArea(radius float64) float64 {
    return math.Pi * radius * radius
}

// The heartbeat of our program is the main function.
func main() {
    var radius float64

    // Prompting the user to specify the circle's radius.
    fmt.Print("Enter the radius of the circle: ")
    fmt.Scan(&radius)

    // Displaying the computed area to the user.
    fmt.Printf("The area of the circle with radius %.2f is: %.2f\n", radius, circleArea(radius))
}

Output:

For instance, if the user inputs a radius of 7, the program's output will elucidate:
The area of the circle with radius 7.00 is: 153.94

4. Step By Step Explanation

1. Package and Import Declarations: Our exploration begins with the package main statement. The fmt package ensures smooth I/O operations, while the math package provides the necessary mathematical constants and functions.

2. Area Calculation Function: The circleArea function is straightforward, using the formula π * radius^2 to determine the circle's area.

3. User Input & Displaying Result: A floating-point variable named radius is initialized to store the user's input. Subsequent to this, the user is prompted to enter the circle's radius. The program then calculates and unveils the circle's area using the circleArea function.