[dFF]

Which is better to hold some values ( like OFFSET_CSDEATHS = 444 ) const or define ?

PHP Code:

const OFFSET_CSDEATHS = 444

or

#define OFFSET_CSDEATHS 444 


?

[Exolent[jNr]]

If you only use it once in your code, use #define.
Otherwise, use a constant.

This is because defines are basically just place holders until it is compiled.
When it is compiled, the define constants are replaced with their actual definition, so the defines are not really constant variables.

Code example:

#define VERSION "1.0"

public plugin_init()
{
    register_plugin("Test", VERSION, "Exolent");
    
    log_amx("Server is running v%s", VERSION);
}

When compiled, it is translated to:

public plugin_init()
{
    register_plugin("Test", "1.0", "Exolent");
    
    log_amx("Server is running v%s", "1.0");
}

The bad thing about this is that those 2 "1.0" strings are in different places of memory, but it is a waste of space since they are the same value.

When you use a constant variable, it is set in a specific place in memory.
When you access that constant variable anywhere, it will use that 1 place in memory.

It is better practice to use constants rather than defines for this reason.
Though, if it is only used once in your code, then a define is okay.

[Dr7sTyLe]

i prefer define

[Exolent[jNr]]

Originally Posted by Dr7sTyLe i prefer define

Opinions don't make code better.

[Devil259]

#define is better because it doesn't use memory -> when the code is compiled, the defines are deleted.
constants use memory because they aren't deleted.

[Exolent[jNr]]

Originally Posted by Devil259 #define is better because it doesn't use memory -> when the code is compiled, the defines are deleted. constants use memory because they aren't deleted.

You are completely wrong.

All strings, characters, numbers, etc. that are written out but not stored in variables, are still stored in memory.

Example:

log_amx("Testing");
log_amx("Testing");
log_amx("Testing");
log_amx("Testing");

"Testing" is in memory 4 times because it appears in 4 different places.

new const string[] = "Testing";

log_amx(string);
log_amx(string);
log_amx(string);
log_amx(string);

Now, "Testing" is only in memory once.

Learn yourself before trying to teach others.

[Devil259]

Originally Posted by Exolent[jNr] You are completely wrong. All strings, characters, numbers, etc. that are written out but not stored in variables, are still stored in memory. Example: log_amx("Testing"); log_amx("Testing"); log_amx("Testing"); log_amx("Testing"); "Testing" is in memory 4 times because it appears in 4 different places. new const string[] = "Testing"; log_amx(string); log_amx(string); log_amx(string); log_amx(string); Now, "Testing" is only in memory once. Learn yourself before trying to teach others.

And where are the defines in this example ? ...

[fysiks]

Originally Posted by Exolent[jNr] Opinions don't make code better.

This made me laugh. So true though.

[Bad_Bud]

Sorry for the necro here, but this is the thread that came up when I performed a google search on the topic.

I'm not buying into the claims being made here, unless some reasonable proof is provided. Typically (I mean in other languages) a #define will be faster than a constant, but if used in excess can bloat the size of the binary, that's the tradeoff. I think this logic is fairly straightforward. However, I replaced all the #defines with constants in one of my plugins, yet instead of shrink the output, the size of the .amxx increased by 7%.

If constants have more restricted usage, increased file size, and slower performance, I don't understand what the benefit is supposed to be, not that an increase of 2kb is going to sway me one way or another, but it does make me question the claims.

[dFF]

Ok, many thanks guys for replies. I will make some tests and I will see wich is more fine, const/define.