Introduction:

Email addresses are a critical part of modern communication, but ensuring that they are properly formatted is important for both validation and security purposes. This program demonstrates how to validate whether a given string is a properly formatted email address using the Go programming language. The goal is to verify that the email follows the structure of `localpart@domain` and includes proper characters, domain name, and a valid extension like `.com` or `.org`.

Objective:

The objective of this program is to write a Go program that takes an email address as input and checks whether it is properly formatted. If the email is valid, it will return `true`; otherwise, it will return `false`.

Code:

package main

import (
    "fmt"
    "regexp"
)

// Function to validate email address
func isValidEmail(email string) bool {
    // Define a regex pattern for email validation
    pattern := `^[a-zA-Z0-9._%+-]+@[a-zA-Z0-9.-]+\.[a-zA-Z]{2,}$`
    re := regexp.MustCompile(pattern)

    // Check if the email matches the pattern
    return re.MatchString(email)
}

func main() {
    var email string
    fmt.Println("Enter email address to validate:")
    fmt.Scanln(&email)

    // Validate the email
    if isValidEmail(email) {
        fmt.Println("The email address is valid.")
    } else {
        fmt.Println("The email address is invalid.")
    }
}

Explanation of the Program Structure:

This Go program works by utilizing regular expressions (regex) to validate email addresses. Here is a breakdown of the key sections:

1. Imports: The program imports two essential packages:
   • fmt: for reading user input and printing the output to the console.
   • regexp: for working with regular expressions to match patterns in strings.
2. isValidEmail function: This function accepts a string (email) and uses a regex pattern to check if the email matches the typical email format. The regex pattern matches a string that has a local part (e.g., `user.name`), followed by the `@` symbol, and then the domain part with a valid extension (e.g., `.com`). If the string matches the pattern, the function returns `true`; otherwise, it returns `false`.
3. Main function: In the main function, the program prompts the user to input an email address. The input is passed to the `isValidEmail` function, which checks if the email is valid. The result is displayed to the user, informing them whether the email is valid or invalid.

How to Run the Program:

1. Ensure that you have Go installed on your machine. If not, download and install Go from the official site: https://go.dev/dl/.
2. Save the code in a file named email_validator.go.
3. Open your terminal or command prompt and navigate to the directory where email_validator.go is saved.
4. Run the command: go run email_validator.go to execute the program.
5. Enter an email address when prompted and the program will tell you whether it is valid or invalid.