php - $errors[] 没有返回

Question

我正在为我的网站构建一个 PHP 登录和注册系统。如果表单字段为空，则编码要求使用 $errors[] 并用于检查输入用户名是否存在于数据库中。即使我没有输入任何信息，我也没有收到任何错误。

登录.php

<?php
include 'cic/initalize.php';

if (user_exists('cassey') === true) {
    echo 'exists';
}
die();

if (empty($_POST) === false) {
    $username = $_POST['username'];
    $password = $_POST['password'];

    if (empty($username) === true || empty($password) === true) {
        $errors[] = 'Please provide your username and password.';
    } else if (user_exists($username) === false) {
        $errors[] = 'We can\'t find the username entered, please enter a valid 
        username or register to continue';
        }
}
?>

clients.php（用户）

<?php
function user_exists($username) {
    $username = sanitize($username);
    return (mysql_result(mysql_query("SELECT userId FROM clients WHERE 
    username = '$username'"), 0) === 1) ? true : false; 
}
?>

调用 login.php 的代码

 <div class="widget">
      <h2>Login | Register</h2>
 </div><!--End widget class tag-->
 <div class="inside">
    <form action="login.php" method="post">
       <ul id="logIn">
          <li>
            Username:<br/>
            <input type="text" name="username"/>
          </li>
          <li>
            Password:<br/>
            <input type="password" name="password"/>
          </li>
          <li>
            <input type="submit" value="Login"/>
          </li>
          <li>
            <a href="register.php">Register</a>
          </li>
       </ul>
    </form>
 </div><!--End inside class tag-->

Answer 1

登录.php：

<?php
ini_set('display_errors', 1);
error_reporting(E_ALL);
include 'cic/initalize.php';

if (user_exists('cassey') === true)
    echo 'exists';
else
    die "User does not exist!";

if (isset($_POST['your_submit_button']) && isset($_POST['username']) && isset($_POST['password']))
{
    $username = $_POST['username'];
    $password = $_POST['password'];

    if (strlen($username)==0  || strlen($password)==0)
    {
        $errors[] = 'Please provide your username and password.';
    }
    elseif(user_exists($username) === false)
    {
        $errors[] = 'We can\'t find the username entered, please enter a valid 
        username or register to continue';
    }
}
else
{
    echo "Error: at least one field wasn't set in the form !<br>";
    print_r($_POST);
}
?>

文档：
isset
empty
ini_set
error_reporting
print_r

替换your_submit_button为 HTML 表单中提交按钮的真实名称。
使用empty()不是一个好主意，因为字符串“0”被认为是空的。您需要检查的是字符串是否至少包含一个字符（长度不等于零）。