How much is the tip for the doorman to open the door in a four-star hotel?

Because the cultures of different places are different, we should consult the local people.

hotels have stars, but tips should not have stars. It is normal to tip even if you don't have it.

it depends on the income and cultural habits of the guests and the cultural habits of the hotel.

For example, 1 dollar, 1 euro, 1~2 Thai pearls, 1 yuan, etc.

I heard that a Korean once gave a tip of 1 cents in a hotel in China, but it was declined.