The RN Ebooks are very good, thanks to those I can enjoy my hobby because I’m not 20 anymore
but sometimes I need clarification about a line (or many lines) of code!

For example:  I stumbled across this line of code:

LV_UNUSED(obj);

Asking ChatGTP (“EXPLAIN LV_UNUSED(obj);”)  I got this explanation:

`LV_UNUSED(obj)` is a macro commonly used in the LVGL (Light and Versatile Graphics Library) to avoid compiler warnings about unused variables. In C and C++, when a variable is declared but not used, some compilers will issue a warning. To suppress these warnings, the `LV_UNUSED` macro is used.

Here’s what happens:
1. `LV_UNUSED(obj)` is designed to “use” the variable `obj` in a way that does nothing but satisfies the compiler.

2. It typically expands to something like `(void)(obj);` — this is a no-op (no operation) that casts the variable to `void`, effectively telling the compiler that you are aware of the variable, and its lack of usage is intentional.
This is particularly useful in cases where certain variables may be conditionally unused (e.g., in different configurations, debugging modes, or depending on compiler flags).

### Example:
void my_function(lv_obj_t * obj) {
LV_UNUSED(obj);
// Function implementation without using 'obj'
}

In this example, LV_UNUSED(obj) prevents a warning when the obj parameter isn’t used in the function.

You also can ask ChatGTP to add comments to the code: TYPE: ADD COMMENTS and then paste the code on the next line.

I hope you will benefit of this! 🙂