Up for a challenge: Enplane to the newbie C programmer the differences in use of volatile , const, and static as applied with scope global, file global and function. Good luck. Fifty years of coding in C (yes, it is still my goto language) I still sometimes get tripped up. But all languages have these problems, as in: Throw the horse over the fence a bale of hay.

Macros are not C "constants"; they are literals. They compiler does not even see macro definitions because they are preprocessed before compilation. They are only constants in the sense that literals are a type of constant, but again, the compiler does not see or process macros. If you look at the preprocessor output, the macros are completely gone.

Cppreference: "Constants, by their simplest definition, are values that do not change."

This is a Video that tries to talk about the intrinsics and fundamental behaviour of 'C' - but fails horribly at that.

It IS a constant. Just not a compile-time constant (such as pre-processor defines, enum values, and C++ constexpr values).

It is worth remembering that when coding for many microcontrollers "const" will place the value in the program store (often times Flash). From a practical point view this means the value will be read-only. This just an addition to already excellent video.

2:17

Hey Jacob,

Actually literals in C (i.e. what

10 is a integer literal.

Great video, in embedded systems we usually use "volatile const uint32_t *reg = 0x04000000u;" to describe a read-only register (like a hypothetical UART RX DATA register). It's not possible to write to the register, but we can read from it, and each time we read it we can get a different value ! And the volatile make it even funnier.

In C (and any language really), the guardrails are there for you and not the machine. Everything depends on your willingness to engage with the languages’ constraints in good faith (unless you’re just breaking things for fun)

What do you mean under "constant is not really constant but read only entity since we intialized it"? How else would you describe or define constant if it is not just read-only entity?

Finally, a great, interesting and professional C content on YT ☺

Thank you, I love your course on C/C++ I have learn so much, I really appreciate what you are doing

I've always liked the

Hey Jacob, great video.

This reminds me of Fortran's numeric literals that are actually variables - they can be modified (mostly by accident) when used as subroutine parameters because of “pass by reference” calling convention.

Since you have posted a clarification video I'm surprised you have not changed the title to this one and also have not pinned a link to the clarification (which has far fewer views than this one).

Before making a video on "exotic" constexpr please explain the const used with pointer and how to declare a