Did you know that you can store 32 true/false values in one single variable? Not only do you save space, but you also get less clutter in your code.

You don't have to understand how the binary numeral system works; however, I recommend it. You can read more about it in this topic, if you're interested.

If you have, say, 100 true/false (bool) per-player variables you would use 195 KB of space. However, if you were to use 4 arrays with bit flags, only 8 KB of space would be used. The outcome would be exactly the same, but you would save 187 KB of space!

Here's an example also containing macros to simplify the usage.

pawn Код:

// Usage for all macros: BitFlag_X(variable, flag)
#define BitFlag_Get(%0,%1)            ((%0) & (%1))   // Returns zero (false) if the flag isn't set.
#define BitFlag_On(%0,%1)             ((%0) |= (%1))  // Turn on a flag.
#define BitFlag_Off(%0,%1)            ((%0) &= ~(%1)) // Turn off a flag.
#define BitFlag_Toggle(%0,%1)         ((%0) ^= (%1))  // Toggle a flag (swap true/false).

enum PlayerFlags:(<<= 1) {
    // It's important that you don't forget to put "= 1" on the first flag. If you don't, all flags will be 0.
    
    PLAYER_IS_LOGGED_IN = 1,   // 0b00000000000000000000000000000001
    PLAYER_HAS_GANG,           // 0b00000000000000000000000000000010
    PLAYER_CAN_BUY_PROPERTIES, // 0b00000000000000000000000000000100
    PLAYER_BLABLA_1,           // 0b00000000000000000000000000001000
    PLAYER_BLABLA_2,           // 0b00000000000000000000000000010000
    PLAYER_BLABLA_3,           // 0b00000000000000000000000000100000
    PLAYER_BLABLA_4,           // 0b00000000000000000000000001000000
    PLAYER_BLABLA_5,           // 0b00000000000000000000000010000000
    PLAYER_BLABLA_6,           // 0b00000000000000000000000100000000
    PLAYER_BLABLA_7,           // 0b00000000000000000000001000000000
    PLAYER_BLABLA_8,           // 0b00000000000000000000010000000000
    PLAYER_BLABLA_9,           // 0b00000000000000000000100000000000
    PLAYER_BLABLA_10,          // 0b00000000000000000001000000000000
    PLAYER_BLABLA_11,          // 0b00000000000000000010000000000000
    PLAYER_BLABLA_12,          // 0b00000000000000000100000000000000
    PLAYER_BLABLA_13,          // 0b00000000000000001000000000000000
    PLAYER_BLABLA_14,          // 0b00000000000000010000000000000000
    PLAYER_BLABLA_15,          // 0b00000000000000100000000000000000
    PLAYER_BLABLA_16,          // 0b00000000000001000000000000000000
    PLAYER_BLABLA_17,          // 0b00000000000010000000000000000000
    PLAYER_BLABLA_18,          // 0b00000000000100000000000000000000
    PLAYER_BLABLA_19,          // 0b00000000001000000000000000000000
    PLAYER_BLABLA_20,          // 0b00000000010000000000000000000000
    PLAYER_BLABLA_21,          // 0b00000000100000000000000000000000
    PLAYER_BLABLA_22           // 0b00000001000000000000000000000000
};

new
    // Create an array with the same tag as the enum
    PlayerFlags:g_PlayerFlags[MAX_PLAYERS]
;

public OnPlayerConnect(playerid) {
    // 0 - All flags are off (false). You must include the tag to prevent a warning.
    g_PlayerFlags[playerid] = PlayerFlags:0;
}

public OnPlayerLogIn(playerid) {
    BitFlag_On(g_PlayerFlags[playerid], PLAYER_IS_LOGGED_IN);
    
//  Without macros:
//  g_PlayerFlags[playerid] |= PLAYER_IS_LOGGED_IN;
}

public OnPlayerJoinGang(playerid) {
    BitFlag_On(g_PlayerFlags[playerid], PLAYER_HAS_GANG);
    
//  Without macros:
//  g_PlayerFlags[playerid] |= PLAYER_HAS_GANG;
}

public OnPlayerLeaveGang(playerid) {
    BitFlag_Off(g_PlayerFlags[playerid], PLAYER_HAS_GANG);
    
//  Without macros:
//  g_PlayerFlags[playerid] &= ~PLAYER_HAS_GANG;
}

public OnPlayerUpdate(playerid) {
    // DoSomething every-other player update.
    
    BitFlag_Toggle(g_PlayerFlags[playerid], PLAYER_BLABLA_19);
    
    if (BitFlag_Get(g_PlayerFlags[playerid], PLAYER_BLABLA_19)) {
        DoSomething();
    }
    
//  Without macros:
//  g_PlayerFlags[playerid] ^= PLAYER_BLABLA_19;
//  
//  if (g_PlayerFlags[playerid] & PLAYER_BLABLA_19) {
//      DoSomething();
//  }
}