The following list of questions was taken from https://www.reddit.com/r/ethereum/comments/72reba/do_you_have_deep_questions_about_solidity_or_the/
An updated summary on the different ways one could have two contracts interact (DELEGATECALL, STATICCALL, libraries, all that stuff) with clear pros/cons for each (gas cost, whether it requires EVM assembly directives, etc)
Question by /u/drcode
I won't talk about low-level opcodes here because of the brevity of the answer. In general, there are four ways functions can be called in Solidity:
