【入门夯实】初值三选：0、空串还是nil的语义决策

local function queryKillBad(actor)
    actor = getplayerbyname(actor)
    local killCnt = 0
    local stored = getplayvar(actor, "HUMAN", "KillCnt")
    if stored ~= nil and stored ~= "" then
        killCnt = tonumber(stored)
    end
    sendmsg(actor, 1, "击杀数：" .. killCnt)
end

local function queryKill(actor)
    actor = getplayerbyname(actor)
    local stored = getplayvar(actor, "HUMAN", "KillCnt")
    local killCnt = tonumber(stored)
    if killCnt == nil then
        sendmsg(actor, 1, "暂无击杀记录。")
        return 0
    end
    sendmsg(actor, 1, "累计击杀 " .. killCnt .. " 只。")
    return killCnt
end

local function isInitialized(actor)
    actor = getplayerbyname(actor)
    return getplayvar(actor, "HUMAN", "InitAt") ~= ""
end