How to quickly understand someone else's code?

Question

Programming

Hey!
How to delve into a big project if you have not participated in its development from the very beginning?
Beginners are often given bug fixing, but as for me, bug fixing is more difficult if a person wrote something himself, IMHO even for middle it is easier to write but not bug fixing.
How to quickly understand someone else's coding and fully integrate into the project?

Answer 1

Ask those around you questions. Mouth. Repeat until you understand