How do I pass a session variable correctly?
Question
I'm really new to PHP, and I'm trying to use the simple captcha mentioned in this question Numeric Captcha for PHP
What I'm trying to do is pass the $_SESSION['captcha'] to my current page, so it can compare with the input I just entered which is supposed to pass by the "form".
Here's my code:
<?php
if(isset($_POST['captcha'] ,$_SESSION['captcha'])) {
if ($_POST['captcha'] == $_SESSION['captcha'])
echo 'YES, YOU DID IT';
}
?>
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>captcha test</title>
</head>
<body>
<form name="input" action="index.php" method="POST">
<img src="captcha.php">
Enter the code above: <input type="text" name="captcha">
<input type="submit" value="Submit">
</form>
</body>
</html>
What's the correct way to do this? How can I implement the captcha in my current code?
3 answers
solution1
1 ACCPTED 2014-06-03 02:43:23
A few things fixed here:
- First you did not use a
session_start()to actually retrieve$_SESSIONvalues. Added here. - Next, you should check if the values are not empty by using
!empty()in addition toisset(). Added here as well. - Finally, I recommend you use
===comparison operator instead of==. While==will check if values are the same,===will check if they are the same and the same data type.
Here is the cleaned up code:
<?php
session_start();
if (isset($_POST['captcha'], $_SESSION['captcha']) &&
!empty($_POST['captcha']) && !empty($_SESSION['captcha'])) {
if ($_POST['captcha'] === $_SESSION['captcha']) {
echo 'YES, YOU DID IT';
}
}
?>
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>captcha test</title>
</head>
<body>
<form name="input" action="index.php" method="POST">
<img src="captcha.php">
Enter the code above: <input type="text" name="captcha">
<input type="submit" value="Submit">
</form>
</body>
</html>
If this still does not work for you, you can dump the values of $_POST and $_SESSION like this to see what you are getting:
echo '<pre>';
print_r($_POST);
echo '</pre>';
echo '<pre>';
print_r($_SESSION);
echo '</pre>';
solution2
0 2014-06-03 02:42:21
You didn't add session_start() at the 1st line, thus the $_SESSION is empty.
Side Note:
- You mixed up XHTML and HTML.
xmlnsis not required for HTML. - DOCTYPE is missing
solution3
0 2014-06-03 02:42:54
You need to start your session with
session_start();
as a first call before your script has any output.
See documentation: http://php.net/manual/en/function.session-start.php
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