php 生成用户名

<?php
function generateRandomUsername($length = 8) {
    $characters = '0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ';
    $username = '';
    for ($i = 0; $i < $length; $i++) {
        $username .= $characters[rand(0, strlen($characters) - 1)];
    }
    return $username;
}

$username = generateRandomUsername();
echo "Generated Username: " . $username;
?>

<?php
function generateUniqueUsername($length = 8) {
    $characters = '0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ';
    do {
        $username = '';
        for ($i = 0; $i < $length; $i++) {
            $username .= $characters[rand(0, strlen($characters) - 1)];
        }
    } while (checkUsernameExists($username));
    return $username;
}

function checkUsernameExists($username) {
    // 这里应该是查询数据库的逻辑
    // 返回true如果用户名已存在，否则返回false
    return false; // 示例中假设用户名不存在
}

$username = generateUniqueUsername();
echo "Generated Unique Username: " . $username;
?>

<?php
function generateValidUsername($length = 8) {
    $characters = '0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ';
    $username = '';
    for ($i = 0; $i < $length; $i++) {
        $username .= $characters[rand(0, strlen($characters) - 1)];
    }
    if (!preg_match('/^[a-zA-Z0-9]+$/', $username)) {
        throw new Exception("Invalid username format");
    }
    return $username;
}

try {
    $username = generateValidUsername();
    echo "Generated Valid Username: " . $username;
} catch (Exception $e) {
    echo "Error: " . $e->getMessage();
}
?>