How to know if a guy likes/ Doesn't like you.

Naruto?

What's a love book without a bit of Naruto?

Nothing. 

If he hits you or playfully punches you on your arm, this may mean he likes you.  

  Play punching can send mixed signals. It could mean "I treat you like one of the boys"  

However, if he continues to think that play punching you is a fun way to hang out, you might be dealing with someone who is never going to get past this immature display of affection

  If you don't like it, say so immediately. You are entitled to ask someone not to harm you.