Cookie page counter in php
Question
I am implementing a php page counter that will keep track of each time the user visits this page until the browser is closed. I am checking to see if the cookie is set, if it is. Then I am increment it and reset its value. But the problem I am having is that the counter is always at two, why is this?
<html>
<head>
<title>Count Page Access</title>
</head>
<body>
<?php
if (!isset($_COOKIE['count']))
{
?>
Welcome! This is the first time you have viewed this page.
<?php
$cookie = 1;
setcookie("count", $cookie);
}
else
{
$cookie = $_COOKIE['count']++;
setcookie("count", $cookie);
?>
You have viewed this page <?= $_COOKIE['count'] ?> times.
<?php }// end else ?>
</body>
</html>
Edit: Thanks everyone, I did the pre increment thing and got it to work
4 answers
solution1
7 2011-10-31 19:55:53
This line is the problem:
$cookie = $_COOKIE['count']++;
It doesn't increment the way you expect; the variable $cookie is set to the value of $_COOKIE , and then $_COOKIE is incremented. It's the postincrement operator.
Use the preincrement operator instead, which increments and then returns:
$cookie = ++$_COOKIE['count'];
solution2
7 ACCPTED 2011-10-31 19:56:12
This is happening because of the ++ being used as a post-increment instead of a pre-increment. Essentially what is happening is you're saying, "set $cookie to the value of $_COOKIE['count'] , and then increment $_COOKIE['count'] . This means that each time you set it you're only actually making $cookie equal 1, and even though $_COOKIE['count'] is showing it as 2, the actual cookie you send will only equal 1. If you do $cookie = ++$_COOKIE['count']; you should get the correct result.
solution3
5 2011-10-31 19:56:27
the _COOKIE array is populated ONCE when the script first starts up (before any code is actually executed), and then is NOT touched again by PHP. Even if you do a setcookie() call to change one of the cookies, that change will NOT take effect until the next page load.
As well, the ++ operator is working in "post-increment" mode. Doing
$cookie = $_COOKIE['count']++;
boils down to this:
$cookie = $_COOKIE['count'];
$_COOKIE['count'] = $_COOKIE['count'] + 1;
What you want is the PRE-increment version:
$cookie = ++$_COOKIE['count'];
which increments the cookie value and THEN assigns it to the cookie var.
solution4
3 2011-10-31 19:56:01
You only need to do this
setcookie('count', isset($_COOKIE['count']) ? $_COOKIE['count']++ : 1);
Like so:
<?php
setcookie('count', isset($_COOKIE['count']) ? $_COOKIE['count']++ : 1);
$visitCount = $_COOKIE['count'];
?>
<html>
<head>
<title>Count Page Access</title>
</head>
<body>
<?if ($visitCount == 1): ?>
Welcome! This is the first time you have viewed this page.
<?else:?>
You have viewed this page <?= $_COOKIE['count'] ?> times.
<?endif;?>
</body>
</html>
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