setting cookie with domain

This is pretty much a basic question since I got 开发者_运维知识库a bit confused

When we set a cookie with domain .mydomain.com refers to use the same cookie over subdomains, what if I do .test.mydomain.com does it mean urls like helloworld.test.mydomain.com will be able to re-use the cookie?

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Yes, that's how it works. There's no special detection of what level the 'subdomains' are, everything is really a subdomain to the TLD at the least. What if you had a .co.uk address?

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Here is an intersting article about sharing cookies across subdomains

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