Re: question about nullptr

On 2024-07-09, Michael S <already5chosen@yahoo.com> wrote:

On Tue, 9 Jul 2024 02:49:49 -0000 (UTC)
Kaz Kylheku <643-408-1753@kylheku.com> wrote:
>

On 2024-07-08, Michael S <already5chosen@yahoo.com> wrote:

On Sun, 07 Jul 2024 15:17:34 -0700
Keith Thompson <Keith.S.Thompson+u@gmail.com> wrote:
 

 
I just about always use NULL, not 0, when I want a null pointer
constant.  Similarly, I use '\0', not 0, when I want a null
character, 0.0 when I want a floating-point zero, and false when I
want a Boolean zero.  I just like being explicit.
 

>
Pointer: I very rarely use NULL.
Character: I never use '\0'.
Floating point: I never use 0.0. 

 
Never say never!
 
  printf("%f\n", 0);   // undefined behavior.
  printf("%f\n", 0.0); // correct
>

>
Yes, but that's extremely rare that I want constant (except string
literal) as variable argument to printf().

Under the paradigm of "I write code only for myself", almost
anything is justifiable.

The "I want" stuff goes out the window as soon as your source code is
consumed by other programmers.  (Interfaced with, patched, taken
over by ...). Anything you define could be used in ways you wouldn't
do yourself.


  // #define GRAV 9.81
  #define GRAV 3

  ...

     printf("configured with\n");
     ...
     printf("GRAV=%g\n", GRAV);

If you're #define-ing a floating-point constant that has
no fractional part, you should put that .0 there.
>

>
I am trying hard to avoid #define-ing floating-point constants.
In rare cases where it is not avoidable, most often the constant does
have fractional part. I am not sure what I would prefer when I can't
avoid #define-ing and the constant has no fractional part. Will I write
something like '#define ANSWER ((double)42)' or (42.0) ?
It depends on the mood of the minute.

You don't need parentheses around 42.0, because the floating point
dot has a higher precedence than any operator. :-)

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