PHP Username Generator

How to Create a Random Username Generator with Vanilla PHP

Watch the full tutorial here:

<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>

<body>
    <form action="./backend.php" method="post">
        <input type="text" name="fname">
        <input type="text" name="lname">
        <button type="submit">generate username</button>
    </form>
</body>

</html>

<?php
if ($_SERVER['REQUEST_METHOD'] === 'POST') {
    $fname = $_POST['fname'];
    $lname = $_POST['lname'];

    function generateRandomString($length = 5)
    {
        return substr(str_shuffle("abcdefghijkmnpqrstuvwxyz23456789"), 0, $length);
    }

    function generateUniqueUsername($fname, $lname)
    {
        $dbExample = [
            'johndoe',
            'alexdoe'
        ];

        $username = strtolower("$fname$lname");

        while (in_array($username, $dbExample)) {
            $username = strtolower("$fname$lname") . generateRandomString();
        }

        return $username;
    }

    echo "Your name: $fname $lname";
    echo "<br>";
    echo "Your username: " . generateUniqueUsername($fname, $lname);
}