[Hawk552]

What is a static variable? It is basically a global variable that can only be accessed by the function it is declared in.

This means that:

#include <amxmodx>
#include <amxmisc>

public plugin_init()
{
    register_plugin("The Internet","Has","Spoken")
    
    fnDoFunc()
    iNum = 2
}

fnDoFunc()
{
    static iNum
    iNum = 1
}

Is NOT valid. Why? Because the static variable was declared in fnDoFunc, not plugin_init.

The example above does not exemplify the true power of static variables. If you're just going to zero it before you use it, use the operator "new". Declaring a new variable is not an expensive operation, simply the zeroing of it is.

But what can a static variable do?

Here's an example of the usage of a static variable vs. a new variable:

Static

#include <amxmodx>
#include <amxmisc>

public plugin_init()
    register_plugin("The Internet","Has","Spoken")

public client_connect(id)
{
    static szName[33]
    
    get_user_name(id,szName,32)
    client_print(0,print_chat,"the matrix has %s",szName)
}

New

#include <amxmodx>
#include <amxmisc>

public plugin_init()
    register_plugin("The Internet","Has","Spoken")

public client_connect(id)
{
    new szName[33]
    get_user_name(id,szName,32)
    client_print(0,print_chat,"the matrix has %s",szName)
}

But why is the static version faster? Because the memory isn't created every single time it's needed, rather it's left there, kind of like a global variable never loses its value ever after being used in a function.

So for example, take in this hypothetical sequence of events in a server:

Static

  static variable initialized
  
  Hawk552 joins server
  client_connect called
  static variable already exists
  get name
  print name
  
  *5 minutes later*
  
  zomg joins server
  client_connect called
  static variable already exists with contents "Hawk552\0..."
  get name -> now looks like "zomg\052\0...", however it ends at the first \0 so the trailing 52 doesn't matter
  print name

New

  Hawk552 joins server
   client_connect called
  new variable initialized
   get name
   print name
  
  *5 minutes later*
  
  zomg joins server
    client_connect called
   new variable initialized
    get name
    print name

And that is basically why static variables are useful.

[3xr]

Thanks for the info. BTW: Happy Birthday.

[Cheap_Suit]

hmmm interesting...

Can you tell me when to use it and when not to use it

[Hawk552]

Originally Posted by Cheap_Suit hmmm interesting... Can you tell me when to use it and when not to use it

Well, in something like a loop, it's pretty useless, like this:

for(static iCount = 0;iCount < x;iCount++)

You'd might as well use new, because the = 0 section of it will make it the same expensiveness as using new. This goes for most other things like = get_user_frags(id) etc.

When using a huge ass array like a motd or menu it's generally best to use static because arrays are a huge hit on CPU, and making it static nullifies that. You must be careful about re-entrancy though, as in something being set from the last time it was used and using it for this instance anyway. If your script is enormous you might start running out of memory in which case you can use #pragma dynamic, with some value like 131072 (which is in bytes)

But as shown in my example one of the best ways to use this is something like:

static szName[33]
get_user_name(id,szName,32)

[Orangutanz]

Originally Posted by Cheap_Suit Can you tell me when to use it and when not to use it

I would imagine a better example would of been if using Forwards such as: PlayerPreThink, StartFrame, Touch etc
All of which are very demanding forwards, so a static would be handy to reduce overhead in the long term.

One annoying thing with static is that you cannot assign as you can with new, example:

new team = get_user_team(id)
static team
team = get_user_team(id)

Also I'm uncertain about this as well:

static team, player

Would player be a static or a new? I assume static but we all know how buggy the Pawn compiler is!

[Hawk552]

Originally Posted by Orangutanz I would imagine a better example would of been if using Forwards such as: PlayerPreThink, StartFrame, Touch etc All of which are very demanding forwards, so a static would be handy to reduce overhead in the long term. One annoying thing with static is that you cannot assign as you can with new, example: new team = get_user_team(id) static team team = get_user_team(id) Also I'm uncertain about this as well: static team, player Would player be a static or a new? I assume static but we all know how buggy the Pawn compiler is!

I'm pretty sure that in your last example they would both be static.

[BAILOPAN]

Using static isn't really necessary if you initialize it like that. It's more appropriate for arrays.

[TheNewt]

(clears throat)

Sorry; I didn't mean to be impolite,

He is apologizing.

just wanted to clear that up in case anyone thought that a static variable

He is announcing what he is clearing up.

suddenly pops up when the line of code where it was declared is executed and then remains there until the universe implodes.

Actually thats worded a bit funky... He is saying when a line of code, is declared, and is executed, in the plugin, that the person whos viewing the code, won't think that the static variable, will stay there untill the end of time... Does that clear it up a bit?

[PM]

Oh perhaps I should have written it more clearly.

The static variable "exists" as long as the plugin is loaded. It is loaded into memory (as a part of the plugin's DAT section) when the plugin is loaded (that is, on map start), and it is freed when the plugin is unloaded (on map end / server shutdown). My point was, the static variable is not "created" when the line it is declared in is first reached. It is in memory as long as the plugin is loaded.