Re: [Dev-C++] #DEFINE versus cont variables in array inicializations

[<or...@vp...>]

André Macário Barros wrote:
> -->My questions:
> 1) Is there more ways to to this?

To hardcode "magic" values :) But it is not an otpion.

> 2) For theese two ways presented here, when use one and when use the other?

Well, C++ encourages people to use const variables instead of #define 
values. But I think there are circumstances, when #define is better. In 
particular, when you HIGHLY optimize for speed in an algorithm, and you 
don't want to use magic values, then it is better to use #define values, 
as the preprocessor replaces them (as if you had typed in the exact 
value) and the compiler can make various optimizations.
For example, when you need to shift with a known value:

i = 1<<SHIFT_VAL;

This case it is better to #define SHIFT_VAL 3 for example, rather than 
const int SHIFT_VAL=3, because in the first case the compiler will 
automatically calculate the value in compile time:

i = 1<<3 --> i = 8;

While this is not true for using const variables (I think, unless the 
compiler is smart), and it takes more time to shift with a variable, 
rather than with a #define. So, another example:
int v;
v<<SHIFT_VAL;
Here v is a variable, and it is faster to shift it if SHIFT_VAL is a 
#define, rather than if SHIFT_VAL is a variable. (I have tested this 
extensively!)

In your case, I don't think you need this type of low-level 
optimisation, so I think you can safely use a const variable.

Hope I could help.
--
Greetings,
   Balázs