CodeIgniter 4 Partially Hide or Mask Email Addresses Tutorial

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In web applications, displaying partially masked email addresses enhances privacy and security by revealing only a portion of the email while retaining its recognizability.

In this tutorial, we’ll explore the process of partially masking email addresses in CodeIgniter 4. This functionality allows developers to display a portion of the email while concealing a part of it, ensuring user privacy without compromising the email’s readability.

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We will use the concept of CodeIgniter 4 helper here to see this concept.





Let’s get started.

CodeIgniter 4 Installation

To create a CodeIgniter 4 setup run this given command into your shell or terminal. Please make sure composer should be installed.

composer create-project codeigniter4/appstarter codeigniter-4

Assuming you have successfully installed application into your local system.

Environment (.env) Setup

When we install CodeIgniter 4, we will have env file at root. To use the environment variables means using variables at global scope we need to do env to .env

Either we can do via renaming file as simple as that. Also we can do by terminal command.

Open project in terminal

cp env .env

Above command will create a copy of env file to .env file. Now we are ready to use environment variables.

Enable Development Mode

CodeIgniter starts up in production mode by default. You need to make it in development mode to see any error if you are working with application.

Open .env file from root.

# CI_ENVIRONMENT = production

 // Do it to 
CI_ENVIRONMENT = development

Now application is in development mode.

Create Custom Helper

Create a file inside /app/Helpers folder with name say custom_helper.php. Inside this naming convention, you can see we have used suffix as _helper.

We have several different codes by which we can mask email addresses. We will see two methods.

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Method #1

Open custom_helper.php file and write following code into it.


// Mask email address with (*) stars
// Example: onl**************@g****.com

if (!function_exists('hideEmailAddress')) {

    function hideEmailAddress($email)
        if (filter_var($email, FILTER_VALIDATE_EMAIL)) {
            list($first, $last) = explode('@', $email);
            $first = str_replace(substr($first, '3'), str_repeat('*', strlen($first) - 3), $first);
            $last = explode('.', $last);
            $last_domain = str_replace(substr($last['0'], '1'), str_repeat('*', strlen($last['0']) - 1), $last['0']);
            $hideEmailAddress = $first . '@' . $last_domain . '.' . $last['1'];
            return $hideEmailAddress;

Method #2

Open custom_helper.php file and write following code into it.


// Mask email address with (*) stars
// Example: onlinewe********

if (!function_exists('hideEmailAddress')) {

    function hideEmailAddress($email)
        $em   = explode("@", $email);
        $name = implode(array_slice($em, 0, count($em) - 1), '@');
        $len  = floor(strlen($name) / 2);
        return substr($name, 0, $len) . str_repeat('*', $len) . "@" . end($em);

Create Controller & Load Helper (Helper Usage)

To create a controller, run this command.

php spark make:controller SiteController

It will create SiteController.php inside /app/Controllers folder.

Open SiteController.php and write this complete code into it.


namespace App\Controllers;

use App\Controllers\BaseController;

class SiteController extends BaseController
	public function index()
		helper("custom"); // loading helper

		$email = '';

        echo hideEmailAddress($email); // Using Method #1 function

Add Route

Open Routes.php from /app/Config folder. Add this route into it.


$routes->get("mask-email", "SiteController::index");

Application Testing

Open project terminal and start development server via command:

php spark serve

URL: http://localhost:8080/mask-email


That’s it.

We hope this article helped you to learn about CodeIgniter 4 Partially Hide or Mask Email Addresses Tutorial in a very detailed way.

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