Another very fine online reference for someone new to C is Beej's Guide to C Programming: https://beej.us/guide/bgc/

(Here is a reference to K&R, the standard first reference to C, because I am obligated to make such a reference.)

I always find, whenever I loan Peter Van der Lindens’ “Deep C Secrets: Expert C Programming” book to a fellow colleague, I never get it back. For a while I had 10 or so spare copies to hand out as treats, but now I just refer everyone to this PDF:

https://progforperf.github.io/Expert_C_Programming.pdf

If you’re a C programmer, old or new, and haven’t encountered this book: Stop What You Are Doing And Go Read It! It’s amazing.

And the K&R reference is useful too. It's a small book about a small language that does not have many features and maps to very basic concepts on hardware that really only does very basic things.

It's so cool! Do you have a similiar resource about c++?