How can I carry cookies in php to multiple subdomain

I want to carry some cookies valu开发者_StackOverflowe to different subdomains like

blog.mydomain.com , profile.mydomain.com , stats.mydomain.com, etc.

Right now I am using below code to set cookies

setcookie('var_name', 'var_value', null, "/", '.mydomain.com' );

With this code, cookies set on blog.mydomain.com available on mydomain.com but not on other subdomain (profile.mydomain.com , stats.mydomain.com, etc.)

Please, let me know, whats wrong with my code .

try:

$res = setcookie('var_name', 'var_value', null, "/", '.mydomain.com' );
var_dump($res); exit;

the output should be TRUE, if you see false it means output exists prior to calling this function and you can't set cookies after beginning sending content

You're doing the correct thing (as far as I know). Refer to the PHP setcookie documentation.

domain

The domain that the cookie is available. To make the cookie available on all subdomains of example.com then you'd set it to '.example.com'.

Do you have any problems retrieving the value on the other domains?