PHP Cookies
PHP Cookies
A cookie is often used to identify a user. A cookie is a small file that the server embeds on the user's computer. Each time the same computer requests a page with a browser, it will send the cookie too. With PHP, you can both create and retrieve cookie values. There are three steps involved in identifying returning users.
Cookies are text files stored on the client computer and they are kept of use tracking purpose. PHP transparently supports HTTP cookies.
- Cookies are text files stored on the client computer and they are kept of use tracking purpose. PHP transparently supports HTTP cookies.
- Browser stores this information on local machine for future use.
- When next time browser sends any request to web server then it sends those cookies information to the server and server uses that information to identify the user.
Create Cookies With PHP
A cookie is created with the setcookie() function. Only the name parameter is required. All other parameters are optional.
its Syntax is: setcookie(name, value, expire, path, domain, secure, httponly);
`Create Cookies With PHP
A cookie is created with the setcookie() function. Only the name parameter is required. All other parameters are optional.
its Syntax is: setcookie(name, value, expire, path, domain, secure, httponly);
PHP Create/Retrieve a Cookie
The following example creates a cookie named "user" with the value "John Doe". The cookie will expire after 30 days (86400 * 30). The "/" means that the cookie is available in entire website (otherwise, select the directory you prefer).
We then retrieve the value of the cookie "user" (using the global variable $_COOKIE). We also use the isset() function to find out if the cookie is set:
The setcookie() function must appear BEFORE the tag. The value of the cookie is automatically URLencoded when sending the cookie, and automatically decoded when received (to prevent URLencoding, use setrawcookie() instead).
<?php
$cookie_name = "user";
$cookie_value = "John Doe";
setcookie($cookie_name, $cookie_value, time() + (86400 * 30), "/"); // 86400 = 1 day
if(!isset($_COOKIE[$cookie_name])) {
echo "Cookie named '" . $cookie_name . "' is not set!";
} else {
echo "Cookie '" . $cookie_name . "' is set!
";
echo "Value is: " . $_COOKIE[$cookie_name];
}
?>
Modify a Cookie Value
To modify a cookie, just set (again) the cookie using the setcookie() function.
`
<?php
$cookie_name = "user";
$cookie_value = "Alex Porter";
setcookie($cookie_name, $cookie_value, time() + (86400 * 30), "/");
if(!isset($_COOKIE[$cookie_name])) {
echo "Cookie named '" . $cookie_name . "' is not set!";
} else {
echo "Cookie '" . $cookie_name . "' is set!
";
echo "Value is: " . $_COOKIE[$cookie_name];
}
?>
Delete a Cookie
Information can be passed to functions through arguments. An argument is just like a variable. Arguments are specified after the function name, inside the parentheses. You can add as many arguments as you want, just separate them with a comma.
The following example has a function with one argument ($fname). When the familyName() function is called, we also pass along a name (e.g. Jani), and the name is used inside the function, which outputs several different first names, but an equal last name:
<?php
// set the expiration date to one hour ago
setcookie("user", "", time() - 3600);
]
echo "Cookie 'user' is deleted.";
?>
Check if Cookies are Enabled
The following example creates a small script that checks whether cookies are enabled. First, try to create a test cookie with the setcookie() function, then count the $_COOKIE array variable:
<?php
setcookie("test_cookie", "test", time() + 3600, '/');
if(count($_COOKIE) > 0) {
echo "Cookies are enabled.";
} else {
echo "Cookies are disabled.";
}
?>
