PHP - 驗證示例

必填欄位將檢查欄位是否以正確的方式填寫。在大多數情況下，我們將使用*符號表示必填欄位。

什麼是驗證？

驗證意味著檢查使用者提交的輸入。PHP 中有兩種型別的驗證可用。它們如下所示：

客戶端驗證 - 驗證在客戶端機器網路瀏覽器上執行。
伺服器端驗證 - 資料提交後，資料將傳送到伺服器，並在伺服器機器上執行驗證檢查。

一些欄位的驗證規則

欄位	驗證規則
姓名	應包含字母和空格
電子郵件	應包含@和.
網站	應包含有效的 URL
單選按鈕	必須至少選擇一次
複選框	必須至少選中一次
下拉選單	必須至少選擇一次

有效 URL

以下程式碼顯示 URL 的驗證

$website = input($_POST["site"]);

if (!preg_match("/\b(?:(?:https?|ftp):\/\/|www\.)[-a-z0-9+&@#\/%?=~_|!:,.;]*[-a-z0-9+&@#\/%=~_|]/i",$website)) {
   $websiteErr = "Invalid URL"; 
}

以上語法將驗證給定的 URL 是否有效。它應允許一些關鍵字，如 https、ftp、www、az、0-9 等。

有效電子郵件

以下程式碼顯示電子郵件地址的驗證

$email = input($_POST["email"]);

if (!filter_var($email, FILTER_VALIDATE_EMAIL)) {
   $emailErr = "Invalid format and please re-enter valid email"; 
}

以上語法將驗證給定的電子郵件地址是否格式正確。如果不是，它將顯示錯誤訊息。

示例

以下示例顯示帶有必填欄位驗證的表單

<html>
   
   <head>
      <style>
         .error {color: #FF0000;}
      </style>
   </head>
   
   <body>
      <?php
         // define variables and set to empty values
         $nameErr = $emailErr = $genderErr = $websiteErr = "";
         $name = $email = $gender = $comment = $website = "";
         
         if ($_SERVER["REQUEST_METHOD"] == "POST") {
            if (empty($_POST["name"])) {
               $nameErr = "Name is required";
            }else {
               $name = test_input($_POST["name"]);
            }
            
            if (empty($_POST["email"])) {
               $emailErr = "Email is required";
            }else {
               $email = test_input($_POST["email"]);
               
               // check if e-mail address is well-formed
               if (!filter_var($email, FILTER_VALIDATE_EMAIL)) {
                  $emailErr = "Invalid email format"; 
               }
            }
            
            if (empty($_POST["website"])) {
               $website = "";
            }else {
               $website = test_input($_POST["website"]);
            }
            
            if (empty($_POST["comment"])) {
               $comment = "";
            }else {
               $comment = test_input($_POST["comment"]);
            }
            
            if (empty($_POST["gender"])) {
               $genderErr = "Gender is required";
            }else {
               $gender = test_input($_POST["gender"]);
            }
         }
         
         function test_input($data) {
            $data = trim($data);
            $data = stripslashes($data);
            $data = htmlspecialchars($data);
            return $data;
         }
      ?>
     
      <h2>Absolute classes registration</h2>
     
      <p><span class = "error">* required field.</span></p>
     
      <form method = "post" action = "<?php 
         echo htmlspecialchars($_SERVER["PHP_SELF"]);?>">
         <table>
            <tr>
               <td>Name:</td>
               <td><input type = "text" name = "name">
                  <span class = "error">* <?php echo $nameErr;?></span>
               </td>
            </tr>
           
            <tr>
               <td>E-mail: </td>
               <td><input type = "text" name = "email">
                  <span class = "error">* <?php echo $emailErr;?></span>
               </td>
            </tr>
           
            <tr>
               <td>Time:</td>
               <td> <input type = "text" name = "website">
                  <span class = "error"><?php echo $websiteErr;?></span>
               </td>
            </tr>
            
            <tr>
               <td>Classes:</td>
               <td> <textarea name = "comment" rows = "5" cols = "40"></textarea></td>
            </tr>
            
            <tr>
               <td>Gender:</td>
               <td>
                  <input type = "radio" name = "gender" value = "female">Female
                  <input type = "radio" name = "gender" value = "male">Male
                  <span class = "error">* <?php echo $genderErr;?></span>
               </td>
            </tr>
				
            <td>
               <input type = "submit" name = "submit" value = "Submit"> 
            </td>
				
         </table>
			
      </form>
      
      <?php
         echo "<h2>Your given values are as:</h2>";
         echo $name;
         echo "<br>";
         
         echo $email;
         echo "<br>";
         
         echo $website;
         echo "<br>";
         
         echo $comment;
         echo "<br>";
         
         echo $gender;
      ?>
   
   </body>
</html>

它將產生以下結果：

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