CodeWithHarry's C++ and OOPs playlist's all codes with commented in-depth notes.
I've tried my best to implement all his programs from the playlist, explain each concept in brief, as well as exhaust all doubt scenarios.
Link to playlist: https://youtube.com/playlist?list=PLu0W_9lII9agpFUAlPFe_VNSlXW5uE0YL&si=gw1pRyGoSUv24L7T