strcmp() 未显示正确的输出 (PHP)

Question

所以这是我的代码，问题是当我在两个字段中输入密码 'malik' 时，我得到的 strcmp() 输出为 5，而密码显然应该为 0，我会附上一张图片让自己清楚。另外，我尝试使用 var_dump($upassword) 和 var_dump($ucpassword) 并且我为它们都得到了 String(5)，所以没有空格。

<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <meta http-equiv="X-UA-Compatible" content="ie=edge">
  <title>Sign-UP</title>
</head>
<body>
  <form action="signup.php" method="post">
  <input type="text" name="uname" placeholder="enter the username">
  <input type="email" name="uemail" placeholder="enter the email" id="">
  <input type="password" name="upassword" placeholder="Password">
  <input type="password" name="ucpassword" placeholder="confirm password">
  <button type="submit" name="registor">Registor</button>
  </form>
</body>
</html>
<?php
if (isset($_POST['registor'])) {
  $uname = $_POST['uname'];
  $uemail = $_POST['uemail'];
  $upassword = (string)$_POST['upassword'];
  $ucpassword = (string)$_POST['ucpassword'];
  echo($uname."<br>");
  echo($uemail."<br>");
  echo($upassword."<br>");
  echo($ucpassword."<br>");
  if($uname == '' || $uemail == '' || $ucpassword = '' || $ucpassword = ''){
    die("Please fill all the fields");
  }
  echo(strcmp($upassword,$ucpassword));
  if(strcmp($upassword,$ucpassword) != 0){
    die("Passwords are not the same");
  }
 }

Answer 1

问题出在这里：

if($uname == '' || $uemail == '' || $ucpassword = '' || $ucpassword = ''){
  die("Please fill all the fields");
}

您正在将 $ucpassword 设置为空字符串。也不要先 $ucpassword 使用 $upassword

应该是这样的：

if($uname == '' || $uemail == '' || $upassword == '' || $ucpassword == ''){
  die("Please fill all the fields");
}

strcmp() 未显示正确的输出 (PHP)

strcmp() not showing proper output (PHP)

php

strcmp