#defines of numeric constants

[CGEngineering]

Hi there,

in my opinion, #defines of numeric constants would lead to a ROM constant, not a RAM variable!.

Example:

Code: Select all

#define NUMBER_OF_REPLIES        5

would be equal to:

Code: Select all

const unsigned short NUMBER_OF_REPLIES = 5;

or, for a string:

Code: Select all

#define myString        "MyStringWithMikroC"

would be equal to:

Code: Select all

const char myString[] = "MyStringWithMikroC";

in order to save RAM, assumed that PICmicros have really a few RAM quantitative

Enjoy!
CG

[idakota]

I might be wrong, but I believe that #defines are compiler directives and the compiler essentially replaces all instances of the defined constant in the source files before compiling, therefore a numeric constant is in fact stored in ROM.

[CGEngineering]

I might be wrong, but I believe that #defines are compiler directives and the compiler essentially replaces all instances of the defined constant in the source files before compiling, therefore a numeric constant is in fact stored in ROM.

Uhm, i noted that numeric constants are stored in rom, but strings don't... so you're right if you say that my post isn't almost correct

I noted, howewer, that is convenient to make a #define or a const everytime a number is written more than once, to avoid immediate addressing with a RAM variable that will never be modified (so can be stored in ROM)

Bye
CG