php表单验证代码

一个php表单验证的演示代码，如果验证失败会在当前页显示提示信息

<?php
 
 
//  Quick function to loop through regexs and compare to what is in _POST
//  
//  $regs    ->   associative array of regular expressions
//  $ferrors ->   error messages to display to the users asociative array
 
function validatePost( $regs , $ferrors )
{
	$errors = array();
	foreach( $regs as $k => $v )
	{
		if( ! preg_match( $v , $_POST[$k] ) )
		{
			$errors[$k] = $ferrors[$k];
		}
	}
	return $errors;
}
 
 
// has the post been submitted?
if( count( $_POST ) )
{
	// yes it has been submitted so lets validate
	$regs['last_name']  = "/^[[:alpha:]\ -]+$/";  // require a alpha
	$regs['first_name'] = "/^[[:alpha:]\ -]+$/";  // require a alpha
	$regs['email']      = "/^..*\@..*$/";         // VERY simple email check
	                                            // Use google to find better
 
 
	// Ok here are the error message to display when it is bad
	$ferrors['last_name']  = "Last name required";
	$ferrors['first_name'] = "First name required";
	$ferrors['email']      = "Email name required";
 
	$errors = validatePost( $regs , $ferrors );
 
	// Do we have errors?
	if( count( $errors ) == 0 )
	{
		//  WE HAVE NO ERRORS DO SOMETHING
		//  PUT IT INTO THE DATABASE, EMAIL, BOUNCE THE USER
		//  TO A THANK YOU PAGE, ETC...
	}
}
?>
 
 
 
<!-- OK WE ARE IN HTML -->
<!-- LETS MAKE THE FORM AND NOW YOU SEE HOW SIMPLE THIS IS I HOPE -->
 
<form method="POST">
 
<p>
<label>Last Name</label>
<input type="text" name="last_name" value="<?= $_POST['last_name'] ?>" />
<span style="color: #FF0000;"><?= $errors['last_name'] ?></span>
</p>
 
 
<p>
<label>First Name</label>
<input type="text" name="first_name" value="<?= $_POST['first_name'] ?>" />
<span style="color: #FF0000;"><?= $errors['first_name'] ?></span>
</p>
 
 
<p>
<label>Email</label>
<input type="text" name="email" value="<?= $_POST['email'] ?>" />
<span style="color: #FF0000;"><?= $errors['email'] ?></span>
</p>
 
 
<p>
<input type="submit" name="subby" value="GO" />
</p>
 
 
</form>