. This title is not very strict. It should be said that dotted cookie names can be used, but they will be converted. You name one. cookie:
<span>$_COOKIE[‘</span>my.name'] = 1;
Actually you cannot find this value in the cookie via 'my.name', only 'my_name':
<span>echo</span> <span>$_COOKIE[‘</span>my_name'];
php has automatically converted it for you, and the period has been converted to an underscore.
Why does php do this? This is because of $_GET/$_POST/$_SERVER/$_COOKIE. . . The values of these global functions can be directly accessed locally through the register_globals parameter in many previous versions. For example, after turning on register_globals = on, accessing $my_name directly takes the value to 1. If it is $my.name, it does not comply with the PHP variable naming principle. This is not just a problem of periods (.).
Therefore, the naming of $_COOKIE already complies with the PHP naming standard.
Also turning on register_globals is a bad decision because it may overwrite the original value in the script, such as:
<span>//</span><span> other code</span> <span>if</span> (<span>$a</span><span>) </span><span>$uc_is_login</span> = <span>true</span><span>; </span><span>//</span><span> ...</span>
Cookies will be included when submitting web pages, so cookies generally do not contain large items, otherwise the web page will be very slow.
This is why images and other resources use different domain names from the main website.
The idea above is not the same as session. Session is the unique PHPSESSID (in cookie) corresponding to each user's session.
Give you a picture of the http request.
date_default_timezone_set("PRC");
setcookie("name","Ronaldiner",time()+3600);
echo "Your name is:". $_COOKIE["name"];
?>