new Spectating[MAX_PLAYERS]; // Creates a variable for MAX_PLAYERS(500)

Spectating[playerid] = 1; // Sets "Specating" to 1 for the player

new string[128], name[MAX_PLAYER_NAME], spectators; // Creates 2 strings, "string" and "name", and a "spectators" variable
format(string, sizeof(string), "Players spectating:"); // Formats "string", making it contain: "Players spectating:"
foreach(Player, i) // Loops through all players, and defines them as "i"
{
    if(Spectating[playerid] == 1) // Checks if "Spectating" is set to 1
    {
        GetPlayerName(i, name, sizeof(name)); // Get's the name of "i"
        strcat(string, " %s", name); // Add's on the name to the string
        spectators ++; // Increases "spectators" by 1
    }
}
switch(spectators) // Creates a switch, checking the value of "spectators"
{
    case 0: SendClientMessage(playerid, -1, "No players are currently spectating anyone.");
        // If "spectators" hasn't been increased (therefore it's value is 0) it will send this message instead

    default: SendClientMessage(playerid, -1, string);
        // If it's set to something else than 0 (players are spectating), it will send the original string
}