[Impact123]

Today i found out an interesting thing about decl, at least for me.
I saved some data in big strings and used decl and strcat for that purpose.
Somehow my strings ended up like that

catval;catval;catval

I realised that declared strings are like static variables.
I never saw this documentated anywhere or i am blind, so i think i may not be the only one who didn't knew this yet.
here is an copy & paste example

Example

PHP Code:

#include <sourcemod>
#pragma semicolon 1




public OnPluginStart()
{
    RegConsoleCmd("sm_test", Command_Test);
}




new g_bStringTerminated;
public Action:Command_Test(client, args)
{    
    decl String:DeclaredString[64];
    // We only terminate once, else our string will be empty again
    if(!g_bStringTerminated)
    {
        DeclaredString[0] = '\0';
        g_bStringTerminated = true;
    }
    
    StrCat(DeclaredString, sizeof(DeclaredString), "x");
    
    
    new String:NormalString[64];
    StrCat(NormalString, sizeof(NormalString), "x");
    
    PrintToServer("DeclaredString: %s", DeclaredString);
    PrintToServer("NormalString: %s", NormalString);
    

    return Plugin_Handled;
} 


The outcome is something like this

DeclaredString: xxxxxxxx
NormalString: x

Why isn't this documentated?

Yours sincerely
Impact

[Mitchell]

Originally Posted by Impact123 Today i found out an interesting thing about decl, at least for me. I saved some data in big strings and used decl and strcat for that purpose. Somehow my strings ended up like that catval;catval;catval I realised that declared strings are like static variables. I never saw this documentated anywhere or i am blind, so i think i may not be the only one who didn't knew this yet. here is an copy & paste example Example PHP Code: #include <sourcemod> #pragma semicolon 1 public OnPluginStart() {     RegConsoleCmd("sm_test", Command_Test); } new g_bStringTerminated; public Action:Command_Test(client, args) {         decl String:DeclaredString[64];     // We only terminate once, else our string will be empty again     if(!g_bStringTerminated)     {         DeclaredString[0] = '\0';         g_bStringTerminated = true;     }          StrCat(DeclaredString, sizeof(DeclaredString), "x");               new String:NormalString[64];     StrCat(NormalString, sizeof(NormalString), "x");          PrintToServer("DeclaredString: %s", DeclaredString);     PrintToServer("NormalString: %s", NormalString);          return Plugin_Handled; }  The outcome is something like this DeclaredString: xxxxxxxx NormalString: x Why isn't this documentated? Yours sincerely Impact

cause usually people format the decl before printing it?

[Silvers]

It is documented... http://wiki.alliedmods.net/Optimizin...n_Local_Arrays

NOTE: You must be very careful not to read from uninitialized variables. They will contain garbage, and you could crash the server by attempting to print or operate on garbage strings.

You should Format or put something into the string first and not expect it to be empty.

[Impact123]

Yeah, i knew that of course.
What i meant to say is i didn't know that decl creates "global" variables.

Yours sincerely
Impact

[hleV]

Yeah, apparently decl creates global (or rather static) variables. Well, back to new then.

[berni]

decl doesn't create a global variable.
You always have to espect that memory which didn't get intialized yet contains garbage random data.

In this case the same memory space just gets reused again.
It's not something you should rely on as it isn't guaranteed, strange things can happen if you do rely on it.

Originally Posted by hleV Yeah, apparently decl creates global (or rather static) variables. Well, back to new then.

The purpose of using decl is to not have to initialize every single cell of the array and save ressources,
I don't know why that would have something todo with a variable being static/global

[Dr. McKay]

As berni said, decl doesn't initialize global/static variables. Rather, it doesn't clear the variable and just reuses whatever memory space it can find. Sometimes, this will be the previous value of it, but do not rely on it as bad things can happen.