PHP cookie Name use dot number (period) will be converted _php Tips

This title is not very strict, it should be said that you can use the dot number of the cookie name, but will be converted, you name a cookie:

$_cookie[' my.name '] = 1;

You can't actually find this value in a cookie by ' my.name ', Only ' my_name ':

echo $_cookie[' My_name '];

PHP has been automatically converted for you, and the period turns to underline.

Why does PHP do this? This is because $_get/$_post/$_server/$_cookie ... The values of these global functions, in many previous versions, can be accessed directly locally via the register_globals parameter, such as when register_globals = On is opened, and the access $my_name takes a direct value of 1. If it is $my.name, it does not conform to the PHP variable naming principle, this is not just a period (.) problem.

Therefore, the naming of $_cookie has already met the PHP naming standard.

Opening register_globals is a bad decision because it may overwrite the original values in the script, such as:

Other code
if ($a)
$uc _is_login = true;
// ...

Users only need to send a url?a=1 HTTP request can be logged by default. This is a very dangerous practice and should be turned off. In fact, PHP6 has removed this option.