PHP Parse error: syntax error, unexpected ',' in

Question

好吧，基本上我正在做一个关于 youtube 的注册和登录教程。它使用旧版本的 PHP，我尝试更新代码，但出现此错误：

Parse error: syntax error, unexpected ',' in C:\Program Files (x86)\EasyPHP-DevServer-14.1VC11\data\localweb\projects\Forum\forum\core\functions\users.php on line 23

users.php

<?php
function user_exists($username, $con) {
    $data = $username;
    $username = sanitize($data, $con); 
    $username = $data;
    mysqli_query($con, "SELECT `user_id` FROM `users` WHERE `username` = '$username'");
    return(mysqli_affected_rows($con) == 1) ? true : false;
}

function user_active($username, $con) {
    $data = $username;
    $username = sanitize($data, $con); 
    $username = $data;
    mysqli_query($con, "SELECT `user_id` FROM `users` WHERE `username` = '$username' AND `active` = 1");
    return(mysqli_affected_rows($con) == 1) ? true : false;
}

function user_id_from_username ($username, $con) {
    $data = $username;
    $username = sanitize($data, $con); 
    $username = $data;
    mysqli_query($con, "SELECT `user_id` FROM `users` WHERE `username` = '$username'");
    return mysqli_affected_rows($con), 0, 'user_id';
}

function login($username, $password, $con) {
    $user_id = user_id_from_username($username, $con);
    $data = $username;
    $username = sanitize($data, $con); 
    $username = $data;
    $password = md5($password); 
    return (mysqli_affected_rows(mysqli_query($con, "SELECT `user_id` FROM `users` WHERE `username` = '$username' AND `password` = '$password'"), 0) == 1) ? $user_id : false;
}
?>

Answer 1

第 23 行是这条：return mysqli_affected_rows($con), 0, 'user_id';

必须是：return mysqli_affected_rows($con) ? 0 : 'user_id';如果这是你的意思。

不能 return PHP 中的多个值。

PHP Parse error: syntax error, unexpected ',' in

PHP Parse error: syntax error, unexpected ',' in

php

return

syntax-error