h007/form_validation_escapechar.php

## form_validation_escapechar.php
<!DOCTYPE HTML>
<html>
<head>
<meta charset="utf-8">
<title>菜鸟教程(runoob.com)</title>
<style>
.error {color: #FF0000;}
</style>
</head>
<body>

<?php
// 定义变量并默认设为空值
$nameErr = $emailErr = $genderErr = $websiteErr = "";
$name = $email = $gender = $comment = $website = "";

if ($_SERVER["REQUEST_METHOD"] == "POST") {
   if (empty($_POST["name"])) {
      $nameErr = "名字是必须的。";
   } else {
      $name = test_input($_POST["name"]);
   }

   if (empty($_POST["email"])) {
      $emailErr = "邮箱是必须的。";
   } else {
      $email = test_input($_POST["email"]);
   }

   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 = "性别是必须的。";
   } 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">* 必填字段。</span></p>
<form method="post" action="<?php echo htmlspecialchars($_SERVER["PHP_SELF"]);?>">
   名字: <input type="text" name="name">
   <span class="error">* <?php echo $nameErr;?></span>
   <br><br>
   E-mail: <input type="text" name="email">
   <span class="error">* <?php echo $emailErr;?></span>
   <br><br>
   网址: <input type="text" name="website">
   <span class="error"><?php echo $websiteErr;?></span>
   <br><br>
   备注: <textarea name="comment" rows="5" cols="40"></textarea>
   <br><br>
   性别:
   <input type="radio" name="gender" value="female">女
   <input type="radio" name="gender" value="male">男
   <span class="error">* <?php echo $genderErr;?></span>
   <br><br>
   <input type="submit" name="submit" value="Submit">
</form>

<?php
echo "<h2>您的输入:</h2>";
echo $name;
echo "<br>";
echo $email;
echo "<br>";
echo $website;
echo "<br>";
echo $comment;
echo "<br>";
echo $gender;
?>

</body>
</html>
	<!DOCTYPE HTML>
	<html>
	<head>
	<meta charset="utf-8">
	<title>菜鸟教程(runoob.com)</title>
	<style>
	.error {color: #FF0000;}
	</style>
	</head>
	<body>

	<?php
	// 定义变量并默认设为空值
	$nameErr = $emailErr = $genderErr = $websiteErr = "";
	$name = $email = $gender = $comment = $website = "";

	if ($_SERVER["REQUEST_METHOD"] == "POST") {
	if (empty($_POST["name"])) {
	$nameErr = "名字是必须的。";
	} else {
	$name = test_input($_POST["name"]);
	}

	if (empty($_POST["email"])) {
	$emailErr = "邮箱是必须的。";
	} else {
	$email = test_input($_POST["email"]);
	}

	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 = "性别是必须的。";
	} 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">* 必填字段。</span></p>
	<form method="post" action="<?php echo htmlspecialchars($_SERVER["PHP_SELF"]);?>">
	名字: <input type="text" name="name">
	<span class="error">* <?php echo $nameErr;?></span>
	<br><br>
	E-mail: <input type="text" name="email">
	<span class="error">* <?php echo $emailErr;?></span>
	<br><br>
	网址: <input type="text" name="website">
	<span class="error"><?php echo $websiteErr;?></span>
	<br><br>
	备注: <textarea name="comment" rows="5" cols="40"></textarea>
	<br><br>
	性别:
	<input type="radio" name="gender" value="female">女
	<input type="radio" name="gender" value="male">男
	<span class="error">* <?php echo $genderErr;?></span>
	<br><br>
	<input type="submit" name="submit" value="Submit">
	</form>

	<?php
	echo "<h2>您的输入:</h2>";
	echo $name;
	echo "<br>";
	echo $email;
	echo "<br>";
	echo $website;
	echo "<br>";
	echo $comment;
	echo "<br>";
	echo $gender;
	?>

	</body>
	</html>