Complete form example

After the user clicks the submit button, to ensure that the field values are entered correctly, we insert a PHP script into the HTML input element. Each field is named: name, email, and website. In the textarea field in the note, we place the script between the <textarea> and </textarea> tags.

The PHP script output values are: $name, $email, $website, and $comment variables.

Then, we also need to check the selected radio button. For this, we must set the checked attribute (not the value attribute of the radio button):

<form method="post" action="<?php echo htmlspecialchars($_SERVER["PHP_SELF"]);?>">
   名字: <input type="text" name="name" value="<?php echo $name;?>">
   <span>* <?php echo $nameErr;?></span>
   <br><br>
   E-mail: <input type="text" name="email" value="<?php echo $email;?>">
   <span>* <?php echo $emailErr;?></span>
   <br><br>
   网址: <input type="text" name="website" value="<?php echo $website;?>">
   <span><?php echo $websiteErr;?></span>
   <br><br>
   备注: <textarea name="comment" rows="5" cols="40"><?php echo $comment;?></textarea>
   <br><br>
   性别:
   <input type="radio" name="gender" <?php if (isset($gender) && $gender=="female") echo "checked";?>  value="female">女
   <input type="radio" name="gender" <?php if (isset($gender) && $gender=="male") echo "checked";?>  value="male">男
   <span>* <?php echo $genderErr;?></span>
   <br><br>
   <input type="submit" name="submit" value="Submit">
</form>

PHP - Complete form example

The following is the complete PHP form verification example code:

<!DOCTYPE HTML> 
 <html>
 <head>
 <meta charset="utf-8">
 <title>php.cn</title>
 <style>
 .error {color: #FF0000;}
 </style>
 </head>
 <body> 
 
 <?php
 // 定义变量并默认设置为空值
 $nameErr = $emailErr = $genderErr = $websiteErr = "";
 $name = $email = $gender = $comment = $website = "";
 
 if ($_SERVER["REQUEST_METHOD"] == "POST")
 {
     if (empty($_POST["name"]))
     {
         $nameErr = "名字是必需的";
     }
     else
     {
         $name = test_input($_POST["name"]);
         // 检测名字是否只包含字母跟空格
         if (!preg_match("/^[a-zA-Z ]*$/",$name))
         {
             $nameErr = "只允许字母和空格"; 
         }
     }
     
     if (empty($_POST["email"]))
     {
       $emailErr = "邮箱是必需的";
     }
     else
     {
         $email = test_input($_POST["email"]);
         // 检测邮箱是否合法
         if (!preg_match("/([\w\-]+\@[\w\-]+\.[\w\-]+)/",$email))
         {
             $emailErr = "非法邮箱格式"; 
         }
     }
     
     if (empty($_POST["website"]))
     {
         $website = "";
     }
     else
     {
         $website = test_input($_POST["website"]);
         // 检测 URL 地址是否合法
         if (!preg_match("/\b(?:(?:https?|ftp):\/\/|www\.)[-a-z0-9+&@#\/%?=~_|!:,.;]*[-a-z0-9+&@#\/%=~_|]/i",$website))
         {
             $websiteErr = "非法的 URL 的地址"; 
         }
     }
     
     if (empty($_POST["comment"]))
     {
         $comment = "";
     }
     else
     {
         $comment = test_input($_POST["comment"]);
     }
     
     if (empty($_POST["gender"]))
     {
         $genderErr = "性别是必需的";
     }
     else
     {
         $gender = test_input($_POST["gender"]);
     }
 }
 
 function test_input($data)
 {
     $data = trim($data);
     $data = stripslashes($data);
     $data = htmlspecialchars($data);
     return $data;
 }
 ?>

 <h2>PHP 表单验证实例</h2>
 <p><span class="error">* 必需字段。</span></p>
 <form method="post" action="<?php echo htmlspecialchars($_SERVER["PHP_SELF"]);?>"> 
    名字: <input type="text" name="name" value="<?php echo $name;?>">
    <span class="error">* <?php echo $nameErr;?></span>
    <br><br>
    E-mail: <input type="text" name="email" value="<?php echo $email;?>">
    <span class="error">* <?php echo $emailErr;?></span>
    <br><br>
    网址: <input type="text" name="website" value="<?php echo $website;?>">
    <span class="error"><?php echo $websiteErr;?></span>
    <br><br>
    备注: <textarea name="comment" rows="5" cols="40"><?php echo $comment;?></textarea>
    <br><br>
    性别:
    <input type="radio" name="gender" <?php if (isset($gender) && $gender=="female") echo "checked";?>  value="female">女
    <input type="radio" name="gender" <?php if (isset($gender) && $gender=="male") echo "checked";?>  value="male">男
    <span class="error">* <?php echo $genderErr;?></span>
    <br><br>
    <input type="submit" name="submit" value="Submit"> 
 </form>
 
 <?php
 echo "<h2>您输入的内容是:</h2>";
 echo $name;
 echo "<br>";
 echo $email;
 echo "<br>";
 echo $website;
 echo "<br>";
 echo $comment;
 echo "<br>";
 echo $gender;
 ?>
 
 </body>
 </html>

Principle: Embed PHP script in the input tag.
If type="text", then embed value="<?php echo $valuableName; ?>"
If type="radio", then embed<?php if (isset($ valuableName) && $valuableName==”value1”) echo “checked”;?>

Next Section

new file

<html>
<head>
 <title>一个简易的登录表单</title>
</head>

<body>
<?php
$email = $passwd ="";
$emailErr=$passwdErr="";

if($_SERVER['REQUEST_METHOD']=='POST'){
 if(empty($_POST['email']))
 $emailErr='请输入邮箱！';
 else if(preg_match("/([\w\-]+\@[\w\-]+\.[\w\-]+)/",$_POST['email']))
 $email=clear_input($_POST['email']);
 else $emailErr="请输入有效的邮箱！";
 if(empty($_POST['passwd']))
 $passwdErr='请输入密码！';
 else
 $passwd=clear_input($_POST['passwd']);
}
function clear_input($data){
 $data=trim($data);
 $data=stripcslashes($data);
 $data=htmlspecialchars($data);
 return $data;
}
?>

<form method="post" action="<?php echo htmlspecialchars($_SERVER['PHP_SELF']);?>">
 邮箱：<input type="text" name="email" value="<?php echo $email;?>" />
 <span class='error'><?php echo $emailErr;?></span>
 <br />
 密码：<input type="password" name="passwd" value="<?php echo $passwd;?>"/>
 <span class='error'><?php echo $passwdErr;?></span>
 <br />
 <input type="submit" name="submit" value="登录">
</form>
<?php
echo "你输入的<br />";
echo "邮箱：".$email;
echo "<br />";
echo "密码：".$passwd;
?>

</body>
</html>

submit Reset Code

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