如何使用PHP驗證表單併發送電子郵件

Question

我已經完成了一小步，但並不好。我想檢查電子郵件是否以正確的格式有效，名稱不包含數字&也如何添加驗證以檢查數學問題是否正確。任何人都可以幫忙嗎？

<?php 
    $submitted = $_POST["submitted"]; 
    if($submitted == "true") 
    { 
    $name = trim($_POST["name"]); 
    $email = trim($_POST["email"]); 
    $subject = trim($_POST["subject"]); 
    $message = trim($_POST["message"]); 
    $answerbox = trim($_POST["answerbox"]); 
    if($name == "") print "<p>Please type your name.</p>"; 
    if($subject == "") print "<p>Please type a subject.</p>"; 
    if($email == "") print "<p>Please type a valid email address.</p>"; 
    if($message == "") print "<p>Please type your message.</p>"; 
    if($answerbox == "") print "<p>Please answer the math question.</p>"; 
    } 

?> 
     <form name="contact" action="form2.php" method="post"> 
      <input type="hidden" name="submitted" value="true"/> 
      <label for="YourName">Your Name:</label> 
      <input type="text" name="name" class="required" /> 

      <label for="YourEmail">Your Email:</label> 
      <input type="text" name="email" class="required"/> 

      <label for="Subject">Subject:</label> 
      <input type="text" name="subject" class="required" /> 

      <label for="YourMessage">Your Message:</label> 
      <textarea name="message" class="required"></textarea> 
      <p class="c3">10 + 5 =<input type="text" name="answerbox" id="answerbox" /></p> 

     <fieldset> 
      <input type="submit" name="submit" id="submit" value="Send" class="required"/> 
      <input type="reset" id="reset" value="Reset"/>  
     </fieldset> 

    </form> 

Answer 1

<?php 
    if(isset($_POST['name'])) 
    { 
    $name = trim($_POST["name"]); 
    $email = trim($_POST["email"]); 
    $subject = trim($_POST["subject"]); 
    $message = trim($_POST["message"]); 
    $answerbox = trim($_POST["answerbox"]); 
    if(strlen($name)<2) { 
     print "<p>Please type your name.</p>"; 
    }else if(strlen($subject)<2) { 
     print "<p>Please type a subject.</p>"; 
    }else if(!filter_var($email, FILTER_VALIDATE_EMAIL)) { 
     print "<p>Please type a valid email address.</p>"; 
    }else if(strlen($message)<10) { 
     print "<p>Please type your message.</p>"; 
    }else if($answerbox != 15) { 
     print "<p>Please answer the math question.</p>"; 
    }else{ 
       $headers = 'From: '.$email. "\r\n" . 
          'Reply-To: '.$email . "\r\n" . 
          'X-Mailer: PHP/' . phpversion(); 
     mail('me@mymail.me',$subject,$message,$headers); 
     print "mail succesuffully sent"; 
    } 

} 
    ?> 

     <form name="contact" action="form2.php" method="post"> 
      <input type="hidden" name="submitted" value="true"/> 
      <label for="YourName">Your Name:</label> 
      <input type="text" name="name" class="required" /> 

      <label for="YourEmail">Your Email:</label> 
      <input type="text" name="email" class="required"/> 

      <label for="Subject">Subject:</label> 
      <input type="text" name="subject" class="required" /> 

      <label for="YourMessage">Your Message:</label> 
      <textarea name="message" class="required"></textarea> 
      <p class="c3">10 + 5 =<input type="text" name="answerbox" id="answerbox" /></p> 

     <fieldset> 
      <input type="submit" name="submit" id="submit" value="Send" class="required"/> 
      <input type="reset" id="reset" value="Reset"/>  
     </fieldset> 

    </form> 

Answer 2

驗證電子郵件是最好的，最安全和最簡單的方法是這樣的：

if (!filter_var($email, FILTER_VALIDATE_EMAIL)) { 
    // invalid emailaddress 
} 

至於其他的答案（尤其是數學的）你不會是最好使用一些javascript在允許表單提交之前，直接在頁面上驗證答案？

的數學可以做這樣的：

if(empty($answerbox)) 
{ 
    echo "<p>Please answer the math question.</p>"; 
} 
elseif ($answer!=15) 
{ 
    echo "Oh oh, the answer seems wrong..."; 
} 
else 
{ 
    // Something else? 
} 

我想你也可能在你的PHP運行在何處以及如何理解不正確。所有PHP代碼在到達用戶之前都會在服務器上執行。在您提交表單並在服務器上處理表單之前，您無法通過PHP檢查答案。