1 .Lua生成隨機(jī)數(shù)：

Lua 生成隨機(jī)數(shù)需要用到兩個(gè)函數(shù)：
math.randomseed(xx)， math.random([n [, m]])

1. math.randomseed(n) 接收一個(gè)整數(shù) n 作為隨機(jī)序列種子。
2. math.random([n [, m]]) 有三種用法： 無參調(diào)用， 產(chǎn)生 （0,1） 之間的浮點(diǎn)隨機(jī)數(shù)； 只有參數(shù) n， 產(chǎn)生 1-n 之間的整數(shù)； 有兩個(gè)參數(shù) n， m， 產(chǎn)生 n-m 之間的隨機(jī)整數(shù)

注：os.time() 返回的時(shí)間是秒級的， 不夠精確， 而 random() 還有個(gè)毛病就是如果 seed 很小或者seed 變化很小，產(chǎn)生的隨機(jī)序列很相似。

解決：把 time返回的數(shù)值字串倒過來（低位變高位）， 再取高位6位。 這樣， 即使 time變化很小， 但是因?yàn)榈臀蛔兞烁呶?#xff0c; 種子數(shù)值變化卻很大，就可以使偽隨機(jī)序列生成的更好一些。

?

2.?

-- 在棋盤范圍內(nèi)，生成n個(gè)隨機(jī)位置(不重復(fù)) CHESSBOARD_MAX = 5*5 function GenRandomPos(n)local pos_list = {}local count = 0math.randomseed(tostring(os.time()):reverse():sub(1, 6)) while(count < n) do local v = math.random(1, CHESSBOARD_MAX)local flag = falsefor j,val in pairs(pos_list) do if val == v thenflag = truebreakendendif not flag thentable.insert(pos_list, v)count = count + 1endendreturn pos_list end

?

3.?

-- 參數(shù):待分割的字符串,分割字符 -- 返回:子串表.(含有空串) function LuaStringSplit(str, split_char)local sub_str_tab = {};while (true) dolocal pos = string.find(str, split_char);if (not pos) thensub_str_tab[#sub_str_tab + 1] = str;break;endlocal sub_str = string.sub(str, 1, pos - 1);sub_str_tab[#sub_str_tab + 1] = sub_str;str = string.sub(str, pos + 1, #str);endreturn sub_str_tab; end

?

4.

(1)

-- 返回當(dāng)前日期數(shù)值 function GeTCurrDateMDY()local date_str = os.date("%x")local date_arr = LuaStringSplit(date_str, "/")local month, day, year = tonumber(date_arr[1]), tonumber(date_arr[2]), tonumber(date_arr[3])return month, day, year end

?

(2)

local open_time_cnf = {{2, 2,}, -- month, day{4, 12,}, } -- 判斷當(dāng)前日期是否在配置表的日期區(qū)間內(nèi)(轉(zhuǎn)換成 時(shí)間戳 進(jìn)行判斷) function IsInDateRange(_open_time_cnf)local today = os.date("*t")local curr_time = os.time({month = today.month, day = today.day, year = 2015,})local start_time = os.time({month = _open_time_cnf[1][1], day = _open_time_cnf[1][2], year = 2015,})local end_time = os.time({month = _open_time_cnf[2][1], day = _open_time_cnf[2][2], year = 2015,})print(start_time, curr_time, end_time)-- os.time的參數(shù)也可以是下面這種-- print(os.time({day=18, month=5, year=2012, hour=0, minute=0, second=0}))return (start_time <= curr_time and curr_time <= end_time) end print(IsInDateRange(open_time_cnf))

?

?

5.

-- Lua 中刪除 table 元素 local test = { 'a','b','c','d','e','f','g','h','i','j','k','l','m','n','o','p' } local test_remove_flag = {}function DoSomething(_table)for k, v in pairs( _table ) do-- 一般我們不在循環(huán)中刪除，在循環(huán)中刪除會造成一些錯(cuò)誤。這是可以建立一個(gè)remove表用來標(biāo)記將要?jiǎng)h除的-- test_remove_flag[k] = (k % 2 == 0) and true or false-- print("------------" ,k, test_remove_flag[k])test_remove_flag[v] = (k % 2 == 0) and true or false-- dosomething
　　　　 -- v 為 列表項(xiàng)_table[k] copy值 end endDoSomething(test)-- 刪除標(biāo)記為true的元素(從后往前刪除) -- table.remove操作后，后面的元素會往前移位，這時(shí)候后續(xù)的刪除索引對應(yīng)的元素已經(jīng)不是之前的索引對應(yīng)的元素了 for i = #test, 1, -1 doif test_remove_flag[test[i]] thentable.remove(test, i)end endfor j = 1, #test doprint(test[j]) end

?

6. 有關(guān)lua全局變量的解析，請參見另一篇博客 lua全局變量和局部變量

-- tab不是一張lua表，或者表為空，則返回true；否則，返回false list = {"a", "b", "c", "d",} function IsTableEmpty(tab)-- tab不是一張表if type(tab) ~= 'table' then return true end-- _G.next(tab) 相當(dāng)于調(diào)用全局next函數(shù)遍歷tab表的下一個(gè)元素return _G.next(tab) == nil end local flag = IsTableEmpty(list) print(flag) ------------------------------------------- -- false-- 所有全局變量都會存在_G里面，_G是一個(gè)table g_var = "global_var." -- 全局變量 print(g_var) print(_G.g_var) local l_var = "local_var." -- 局部變量 print(l_var) print(_G.l_var) --------------------------------------------- -- global_var. -- global_var. -- local_var. -- nil -- [Finished in 0.1s]

7.?

?

CnfShopYouHui = {[4] = {name = "技能石",},[5] = {name = "強(qiáng)化石",},[6] = {name = "仙寵品階丹",},[1] = {name = "小花束",},[2] = {name = "大花束",},[3] = {name = "豪華花束",}, };local temp_cnf = CnfShopYouHuifor i, item in pairs(CnfShopYouHui) do print(" ------------ > ", i, item.name) end-- temp_cnf 是對CnfShopYouHui的一個(gè)引用，修改team_cnf會導(dǎo)致CnfShopYouHui也被修改 table.remove(temp_cnf, 1) print(" ********************************** ")for i, item in pairs(CnfShopYouHui) do print(" ------------ > ", i, item.name) end-- output------------ > 6 仙寵品階丹------------ > 2 大花束------------ > 3 豪華花束------------ > 1 小花束------------ > 4 技能石------------ > 5 強(qiáng)化石********************************** ------------ > 2 豪華花束------------ > 3 技能石------------ > 1 大花束------------ > 4 強(qiáng)化石------------ > 5 仙寵品階丹 [Finished in 0.1s]

?

8.

?

CnfShopYouHui = {[4] = {name = "技能石",},[5] = {name = "強(qiáng)化石",},[6] = {name = "仙寵品階丹",},[1] = {name = "小花束",},[2] = {name = "大花束",},[3] = {name = "豪華花束",}, };for i, item in pairs(CnfShopYouHui) doif 1 == i then table.remove(CnfShopYouHui, 1)CnfShopYouHui[i] = nilend-- i, item 是CnfShopYouHui內(nèi)容項(xiàng)的(值)復(fù)制，CnfShopYouHui[i]是內(nèi)容項(xiàng)本身的(引用)-- 所以，雖然上面刪除了table.remove(CnfShopYouHui, 1)， 但此時(shí)item已經(jīng)復(fù)制了它的值。print(" ------------ > ", i, item.name, CnfShopYouHui[i]) end-- output------------ > 6 仙寵品階丹 table: 004FC270------------ > 2 大花束 table: 004FC310------------ > 3 豪華花束 table: 004FC360------------ > 1 小花束 nil------------ > 4 強(qiáng)化石 table: 004FC220------------ > 5 仙寵品階丹 table: 004FC270 [Finished in 0.1s]

10.

?

--*************************************************-- -- 樹形打印table成員(table, variable, function ……) local tablePrinted = {} function printTableItem(k, v, tab)for i = 1, tab doio.write(" ") -- 縮進(jìn)endio.write(tostring(k), " = ", tostring(v), "\n")if type(v) == "table" thenif not tablePrinted[v] thentablePrinted[v] = truefor k, v in pairs(v) do-- tab 非局部變量(Upvalue) printTableItem(k, v, tab + 1)endendend end--*************************************************---- lfs(Lua file system, lfs.dll 動態(tài)庫), 在lua的安裝目錄下就有此動態(tài)庫-- D:\5.1\clibs require "lfs" -- 打印當(dāng)前文件路徑 print("-- lfs.currentdir() -------------------------------------------- ") print(lfs.currentdir())print("-- printTableItem lfs -------------------------------------------- ") -- 查看lfs.dll動態(tài)庫 成員 printTableItem("lfs", lfs, 0) -- -- 打印全局表_G -- -- printTableItem("_G", _G, 0)local file_name = "D:/tes.lua" -- D:\tes.lua (絕對路徑和相對路徑) local t = lfs.attributes(file_name) -- 取文件全部屬性 print("-- lfs.attributes D:/tes.lua -------------------------------------------- ") for k, data in pairs(t) doprint(tostring(k)) endprint("-- modify_time -------------------------------------------- ") local modify_time = lfs.attributes(file_name, "modification") -- 取文件一個(gè)屬性 print(tostring(modify_time))print(" END -------------------------------------------- ") -- output -- lfs.currentdir() -------------------------------------------- D:\ -- printTableItem lfs -------------------------------------------- lfs = table: 004EB518symlinkattributes = function: 004ECF28dir = function: 004ECE28_VERSION = LuaFileSystem 1.4.2setmode = function: 004ECF48unlock = function: 004ECFC8_DESCRIPTION = LuaFileSystem is a Lua library developed to complement the set of functions related to file systems offered by the standard Lua distributioncurrentdir = function: 004ECE08_COPYRIGHT = Copyright (C) 2003 Kepler Projectattributes = function: 004ECDA8lock = function: 004ECE68touch = function: 004ECF88mkdir = function: 004ECEA8chdir = function: 004ECDC8rmdir = function: 004ECEE8 -- lfs.attributes D:/tes.lua -------------------------------------------- dev change access rdev nlink uid gid ino mode modification size -- modify_time -------------------------------------------- 1426498014END -------------------------------------------- [Finished in 0.2s]

?

11. lua腳本熱加載

（1）首先在D:\路徑下創(chuàng)建以下三個(gè)文件：

-- D:\add.luafunction add_func()local x, y = 12, 32print(">>>>>>>>>>>>>>add_func(12, 32)：x+y = " .. tostring(x+y)) end add_func() -- D:\dive.luafunction dive_func()local x, y = 12, 3print(">>>>>>>>>>>>>>dive_func(12, 3)：x / y = " .. tostring(x/y)) end dive_func() -- D:\hotreload.lua--*************************************************-- SCRIPTLIST = {"add","dive", } ----[[ -- 實(shí)現(xiàn)lua腳本的熱加載 pre_modify_time = 0 -- 模擬原始改變時(shí)間 function HotReload(name_str)if name_str thenlocal module_name = name_strprint(" >>>>>>>>>>>>>> name_str", name_str)package.loaded[module_name] = nilrequire(module_name)elserequire "lfs"print(lfs.currentdir()) -- D:\for _, module_name in pairs(SCRIPTLIST) dolocal file_name = lfs.currentdir() .. module_name .. ".lua"local modify_time = lfs.attributes(file_name, "modification")print("file_name, pre_modify_time, modify_time", file_name, pre_modify_time, modify_time)if modify_time > pre_modify_time thenpackage.loaded[module_name] = nilrequire(module_name)endendend end --]] HotReload()

（2）執(zhí)行hotreload.lua文件，輸出如下：

D:\ file_name, pre_modify_time, modify_time D:\add.lua 0 1426502029 >>>>>>>>>>>>>>add_func(12, 32)：x+y = 44 file_name, pre_modify_time, modify_time D:\dive.lua 0 1426502032 >>>>>>>>>>>>>>dive_func(12, 3)：x / y = 4 [Finished in 0.2s]

12.

-- lua賦值操作中，如果賦值table是采用引用方式賦值；(userdata等類型還未檢驗(yàn)) -- 如果賦值常規(guī)變量(string,number,...等類型)則采用值傳遞方式賦值。 local a, b = 31, 42 local copy_a = a local change_b = b change_b = change_b + 1 print(" ---------------- a, copy_a = ", a, copy_a) print(" ---------------- b, change_b = ", b, change_b)local str = "test_str" local change_str = str change_str = change_str .. "_add_str" print(" ---------------- str, change_str = ", str, change_str)-- table local t = {"a", "b", "d", "e",} local change_t = t table.remove(change_t, 1) for i, v in pairs(t) doprint(" -------------- ", v) end-- function local add = function(x, y)print(" ----------- add(x, y) = ", x + y) end local dive = add dive = function(x, y)print(" ----------- dive(x, y) = ", x/y) end add(12, 3) dive(12, 3)

-- output

---------------- a, copy_a = 31 31---------------- b, change_b = 42 43---------------- str, change_str = test_str test_str_add_str-------------- b-------------- d-------------- e----------- add(x, y) = 15----------- dive(x, y) = 4 [Finished in 0.1s]

?

13.

?

local test_str = "my_test_str" local testt = { list = {"a", "b", "c", "d",list_1 = {"e", "f", "g",},},limit_value=31,limit_type=1,list_t = list,list_tt = testt,list_ttt = limit_value,list_tttt = test_str, } print(" >>>>>>>>>>>>>>>>> testt.list_ttt, testt.limit_value, testt.list_tttt = ", testt.list_ttt, testt.limit_value, testt.list_tttt) -- 注：由于在表testt內(nèi)定義list_ttt的時(shí)候，表testt還沒定義結(jié)束，此時(shí)limit_value為nil，所以list_ttt輸出為nil； -- 而test_str在表testt之前定義完成，所以可以在表testt內(nèi)對字段list_tttt賦值； -- 同時(shí)，當(dāng)打印testt.limit_value時(shí)，表testt和表內(nèi)字段都已經(jīng)定義完成。 --------------------------------------------------------------------------- ipairs 和 pairs 的lua的table遍歷的區(qū)別 print(" >>>>>>>>>>>>>>>>> ipairs") for j, item in ipairs(testt) doprint(j) end print(" >>>>>>>>>>>>>>>>> pairs") for j, item in pairs(testt) doprint(j) end-- 取表長度# 原理和 (i)pairs 一樣，table.sort 也類似，等等。 print(" ---------------- #testt", tostring(#testt)) -- lua中取table長度操作(#table_name)是基于Array的table local list_l = {"a", "b", "c", "d",} print(" ---------------- #list_l", tostring(#list_l)) --------------------------------------------------------------------------- foreach遍歷整張table, #list_k只打印符合array(以 1 開始的連續(xù)整數(shù)作為key的table)的連續(xù)下標(biāo)的值 local list_k = {aa = "a", bb = "b", [2] = "c", [3] = "d", [4] = "e", [5] = "f",} local list_k_2 = {aa = "a", bb = "b", "c", "d", [4] = "e", [5] = "f",} table.foreach(list_k, function(i, v)print(" ---------------- i, v = ", i, v)end) print(" ---------------- #list_k = ", tostring(#list_k)) print(" ---------------- #list_k_2 = ", tostring(#list_k_2))

-- output

>>>>>>>>>>>>>>>>> testt.list_ttt, testt.limit_value, testt.list_tttt = nil 31 my_test_str>>>>>>>>>>>>>>>>> ipairs>>>>>>>>>>>>>>>>> pairs limit_value list list_tttt limit_type---------------- #testt 0---------------- #list_l 4---------------- i, v = 2 c---------------- i, v = aa a---------------- i, v = 3 d---------------- i, v = 4 e---------------- i, v = 5 f---------------- i, v = bb b---------------- #list_k = 0---------------- #list_k_2 = 2 [Finished in 0.1s]

14.

?

function table.isArray(tab)if not tab thenreturn falseendlocal ret = truelocal idx = 1for f, v in pairs(tab) doif type(f) == "number" thenif f ~= idx thenret = falseendelseret = falseendif not ret then break endidx = idx + 1endreturn ret end-- table序列化 serialize --序列化一個(gè)Table function serialize(t)local assign={}local function table2str(t, parent)local ret = {}if table.isArray(t) thentable.foreach(t, function(i, v)local k = tostring(i)local dotkey = parent.."["..k.."]"local t = type(v)if t == "userdata" or t == "function" or t == "thread" or t == "proto" or t == "upval" then--ignoreelseif t == "table" thentable.insert(ret, table2str(v, dotkey))elseif t == "string" thentable.insert(ret, string.format("%q", v))elseif t == "number" thenif v == math.huge thentable.insert(ret, "math.huge")elseif v == -math.huge thentable.insert(ret, "-math.huge")elsetable.insert(ret, tostring(v))endelsetable.insert(ret, tostring(v))endend)else table.foreach(t, function(f, v)local k = type(f)=="number" and "["..f.."]" or flocal dotkey = parent..(type(f)=="number" and k or "."..k)local t = type(v)if t == "userdata" or t == "function" or t == "thread" or t == "proto" or t == "upval" then--ignoreelseif t == "table" thentable.insert(ret, string.format("%s=%s", k, table2str(v, dotkey)))elseif t == "string" thentable.insert(ret, string.format("%s=%q", k, v))elseif t == "number" thenif v == math.huge thentable.insert(ret, string.format("%s=%s", k, "math.huge"))elseif v == -math.huge thentable.insert(ret, string.format("%s=%s", k, "-math.huge"))elsetable.insert(ret, string.format("%s=%s", k, tostring(v)))endelsetable.insert(ret, string.format("%s=%s", k, tostring(v)))endend)end-- table.concat 遍歷ret并使用","分隔元素return "{"..table.concat(ret,",").."}"endif type(t) == "table" then -- 調(diào)用table2str入口return string.format("%s", table2str(t,"_"))elsereturn tostring(t)end end local testt = { limit_value=31,limit_type=1,list = {"a", "b", "c", "d",list_1 = {"e", "f", "g",}, list_2 = testt,},my_list_1 = {"111", "222", "333", "4444", "555",}, } print(serialize(testt))

-- output

{limit_value=31,my_list_1={"111","222","333","4444","555"},list={[1]="a",[2]="b",[3]="c",[4]="d",list_1={"e","f","g"}},limit_type=1} [Finished in 0.2s]

?15.

GameConfig = {} GameConfig.ResCompose = {} GameConfig.ResCompose.Effects_E612 = {Path = "resource/language/gt/effects/e612.png",ScaleSize = 0.5,FrameInterval = 0.125,[1] = { 1494, 0, 228, 151, 3, 4, },[2] = { 660, 0, 284, 244, 1, -85, },[3] = { 336, 0, 323, 249, 0, -82, },-- [4] = { 0, 0, 335, 250, 2, -81, }, [5] = { 1226, 0, 267, 240, -2, -91, },[6] = { 945, 0, 280, 242, -3, -87, }, } print(" >>>>>>>>>>>>>>>>>>>>> 1") -- table.getn(table_name) 獲取table_name中連續(xù)id的元素個(gè)數(shù) print(table.getn(GameConfig.ResCompose.Effects_E612)) -- 3 print(" >>>>>>>>>>>>>>>>>>>>> 2")

?16.文件操作

-- 打開文件讀取 function OpenFile(path)local content = ""local file = io.open(path, "r")if (not file) then-- 打開失敗return nilendfor line in file:lines() docontent = content .. line .. "\n"endfile:close(path)return content-- 寫入文件-- local file = io.open(path, "w")-- file:write(content)-- file:close() end -- 調(diào)用 -- local str = OpenFile("luafiletest.txt")-- 重命名文件 function ChangeFileName(path)local status = ""local file = io.open(path, "r")file:close(path) -- 關(guān)閉之后才能重命名local status = os.rename(path, path..".bak")if (not status) then-- 重命名失敗returnendreturn status end -- local status = ChangeFileName("luafiletest.txt")

?17.字符串和數(shù)字比較

18.

-- 將字符串轉(zhuǎn)成table function stringToTable(str) local ret = loadstring("return "..str)() return ret end str = "{1}, print('run print')" local test = stringToTable(str) for i, v in pairs(test) doprint(i, v) endlocal str_s = "print('test print')" print(str_s)

?

轉(zhuǎn)載于:https://www.cnblogs.com/yyxt/p/4180596.html

與50位技術(shù)專家面對面20年技術(shù)見證，附贈技術(shù)全景圖

總結(jié)

以上是生活随笔為你收集整理的lua常用操作的全部內(nèi)容，希望文章能夠幫你解決所遇到的問題。

如果覺得生活随笔網(wǎng)站內(nèi)容還不錯(cuò)，歡迎將生活随笔推薦給好友。