lua 打乱顺序算法

      local numArr = {"red", "green", "white"}
      --洗牌算法,打乱后三张顺序
      for i = #numArr ,1,-1 do
          local index = math.random(1, #numArr)
          self.zTable[numArr[i]] , self.zTable[numArr[index]] = self.zTable[numArr[index]] , self.zTable[numArr[i]]
      end