php cookies
What is a Cookie?
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.
Create Cookies With PHP
A cookie is created with the setcookie() function.
Syntax
setcookie(name, value, expire, path, domain, secure, httponly);
Only the name parameter is required. All other parameters are
optional.
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
$_COOKIE). We also use the isset() function to find out if the cookie is set:
Example
<?php$cookie_name = "user";$cookie_value = "John Doe";setcookie($cookie_name, $cookie_value, time() + (86400 * 30), "/"); // 86400 = 1 day?><html><body><?phpif(!isset($_COOKIE[$cookie_name])) {
echo "Cookie named '" . $cookie_name . "' is not set!";} else {
echo "Cookie '" . $cookie_name . "' is set!<br>"; echo "Value is: " . $_COOKIE[$cookie_name];}?></body></html>
Note: The setcookie() function must appear BEFORE the <html> tag.
Note: The value of the cookie is automatically URLencoded when
sending the cookie, and automatically decoded when received (to prevent
URLencoding, use setrawcookie() instead).
Modify a Cookie Value
To modify a cookie, just set (again) the cookie using the setcookie() function:
Example
<?php$cookie_name = "user";$cookie_value = "Alex Porter";
setcookie($cookie_name, $cookie_value, time() + (86400 * 30), "/");?><html><body><?phpif(!isset($_COOKIE[$cookie_name])) {
echo "Cookie named '" . $cookie_name . "' is not set!";} else {
echo "Cookie '" . $cookie_name . "' is set!<br>";
echo "Value is: " . $_COOKIE[$cookie_name];}?></body></html>
Delete a Cookie
To delete a cookie, use the setcookie() function with an expiration date in
the past:
Example
<?php// set the expiration date to one hour agosetcookie("user", "", time() - 3600);?><html><body><?phpecho "Cookie 'user' is deleted.";?></body></html>
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 $_COOKIE array variable:
Example
<?phpsetcookie("test_cookie", "test", time() + 3600, '/');?><html><body><?phpif(count($_COOKIE) > 0) { echo "Cookies are enabled.";} else {
echo "Cookies are disabled.";}
?></body></html>
Complete PHP Network Reference
For a complete reference of Network functions, go to our complete
PHP Network Reference.
PHP Exercises
Test Yourself With Exercises
Exercise:
Create a cookie named "username".
("username", "John", time() + (86400 * 30), "/");
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