WHEN do YOU consider somebody your friend?

I asked a question already concerning this, but I guess I did not word it the right way and thus got answers that I did not expect.

WHEN do you consider somebody your friend? And when I say ‘friend’, I don’t mean somebody who has seen them in their worse and still stays back to help, nor am I asking who ‘true friends’ are at all.

Ex1) Somebody you talk to everyday in class about a lot of personal things.. Are they your friend, or just some random person to talk to in class and share stuff?

Ex2) Somebody you always talk to at work, also share personal stuff about life but don’t hang out out of work.

Ex3) Somebody you worked with on a group project and got in some good conversations about personal topics

Ex1,2 and 3, friend or acquaintance?!

From the above, sometimes people only think of the person they share things with to be a mere acquaintance, or somebody to talk to. When do you actually consider somebody your friend? And what if you’re unsure that they don’t consider you as a friend in return?

I don’t know if it’s just me who thinks this way, so I want to see other people’s point of views. Please leave your thoughts!