====== getPlayerTotal ======

----

  * Parameters and types:
     * alive: numberplayer status (0 means dead, 1 means alive, default -1 means all players)
    * Return value and type:
    * code: numberSuccess (ErrorCode.OK) ErrorCode
      * num: numberGet the number
  * The main function of this method: Get the total number of players
  * The specific use cases are as follows:

<code>
--Get the total number of players in the current archive
local result,num=World:getPlayerTotal(-1)
Chat:sendSystemMsg("The total number of players in the current archive is:"..num)
--Get the number of players who died in the current archive
result,num=World:getPlayerTotal(0)
Chat:sendSystemMsg("The number of players who died in the current archive is:"..num)
--Get the number of players who are alive in the current archive
result,num=World:getPlayerTotal(1)
Chat:sendSystemMsg("The number of players who are alive in the current archive is:"..num)
</code>