【lua工具类】lua-table 和 string 和 json 的相互转换..._学生董格_lua table转json

网络投稿 02-07 7232

【lua工具类】lua-table 和 string 和 json 的相互转换... 1.lua table2.string3.json4.lua中的写法5.在线运行结果...6.参考/在线工具:

1.lua table

Lua table(表)

table 是 Lua 的一种数据结构用来帮助我们创建不同的数据类型，如：数组、字典等。

Lua table 使用关联型数组，你可以用任意类型的值来作数组的索引，但这个值不能是 nil。

Lua table 是不固定大小的，你可以根据自己需要进行扩容。

Lua也是通过table来解决模块（module）、包（package）和对象（Object）的。例如string.format表示使用"format"来索引table string。

2.string

String就是C++、java、VB等编程语言中的字符串，用双引号引起来的几个字符，如"Abc",“一天”.

3.json

简单地说，JSON 可以将 JavaScript 对象中表示的一组数据转换为字符串，然后就可以在网络或者程序之间轻松地传递这个字符串，并在需要的时候将它还原为各编程语言所支持的数据格式，例如在 PHP 中，可以将 JSON 还原为数组或者一个基本对象。在用到AJAX时，如果需要用到数组传值，这时就需要用JSON将数组转化为字符串.

一些合法的JSON的实例：

{“a”: 1, “b”: [1, 2, 3]} [1, 2, “3”, {“a”: 4}]

4.lua中的写法 Utils = {} ---------------------------------------------------------------------------------- -- Lua-Table 与 string 转换 local function value2string(value, isArray) if type(value)=='table' then return Utils.table2string(value, isArray) elseif type(value)=='string' then return "\""..value.."\"" else return tostring(value) end end function Utils.string2table(str) if str == nil or type(str) ~= "string" or str == "" then return {} end --若报错bad argument #1 to 'loadstring' ... ，把loadstring改为load即可 --return loadstring("return " .. str)() return load("return " .. str)() end function Utils.table2string(t, isArray) if t == nil then return "" end local sStart = "{" local i = 1 for key,value in pairs(t) do local sSplit = "," if i==1 then sSplit = "" end if isArray then sStart = sStart..sSplit..value2string(value, isArray) else if type(key)=='number' or type(key) == 'string' then sStart = sStart..sSplit..'['..value2string(key).."]="..value2string(value) else if type(key)=='userdata' then sStart = sStart..sSplit.."*s"..Utils.table2string(getmetatable(key)).."*e".."="..value2string(value) else sStart = sStart..sSplit..key.."="..value2string(value) end end end i = i+1 end sStart = sStart.."}" return sStart end ---------------------------------------------------------------------------------- -- Lua-Table 与 json 转换 local function json2true(str, from, to) return true, from + 3 end local function json2false(str, from, to) return false, from + 4 end local function json2null(str, from, to) return nil, from + 3 end local function json2nan(str, from, to) return nil, from + 2 end local numberchars = { ['-'] = true, ['+'] = true, ['.'] = true, ['0'] = true, ['1'] = true, ['2'] = true, ['3'] = true, ['4'] = true, ['5'] = true, ['6'] = true, ['7'] = true, ['8'] = true, ['9'] = true, } local function json2number(str, from, to) local i = from + 1 while (i <= to) do local char = string.sub(str, i, i) if not numberchars[char] then break end i = i + 1 end local num = tonumber(string.sub(str, from, i - 1)) if not num then return end return num, i - 1 end local function json2string(str, from, to) local ignor = false for i = from + 1, to do local char = string.sub(str, i, i) if not ignor then if char == '\"' then return string.sub(str, from + 1, i - 1), i elseif char == '\\' then ignor = true end else ignor = false end end end local function json2array(str, from, to) local result = {} from = from or 1 local pos = from + 1 local to = to or string.len(str) while (pos <= to) do local char = string.sub(str, pos, pos) if char == '\"' then result[#result + 1], pos = json2string(str, pos, to) --[[ elseif char == ' ' then elseif char == ':' then elseif char == ',' then]] elseif char == '[' then result[#result + 1], pos = json2array(str, pos, to) elseif char == '{' then result[#result + 1], pos = Utils.json2table(str, pos, to) elseif char == ']' then return result, pos elseif (char == 'f' or char == 'F') then result[#result + 1], pos = json2false(str, pos, to) elseif (char == 't' or char == 'T') then result[#result + 1], pos = json2true(str, pos, to) elseif (char == 'n') then result[#result + 1], pos = json2null(str, pos, to) elseif (char == 'N') then result[#result + 1], pos = json2nan(str, pos, to) elseif numberchars[char] then result[#result + 1], pos = json2number(str, pos, to) end pos = pos + 1 end end local function string2json(key, value) return string.format("\"%s\":\"%s\",", key, value) end local function number2json(key, value) return string.format("\"%s\":%s,", key, value) end local function boolean2json(key, value) value = value == nil and false or value return string.format("\"%s\":%s,", key, tostring(value)) end local function array2json(key, value) local str = "[" for k, v in pairs(value) do str = str .. Utils.table2json(v) .. "," end str = string.sub(str, 1, string.len(str) - 1) .. "]" return string.format("\"%s\":%s,", key, str) end local function isArrayTable(t) if type(t) ~= "table" then return false end local n = #t for i, v in pairs(t) do if type(i) ~= "number" then return false end if i > n then return false end end return true end local function table2json(key, value) if isArrayTable(value) then return array2json(key, value) end local tableStr = Utils.table2json(value) return string.format("\"%s\":%s,", key, tableStr) end function Utils.json2table(str, from, to) local result = {} from = from or 1 local pos = from + 1 local to = to or string.len(str) local key while (pos <= to) do local char = string.sub(str, pos, pos) if char == '\"' then if not key then key, pos = json2string(str, pos, to) else result[key], pos = json2string(str, pos, to) key = nil end --[[ elseif char == ' ' then elseif char == ':' then elseif char == ',' then]] elseif char == '[' then if not key then key, pos = json2array(str, pos, to) else result[key], pos = json2array(str, pos, to) key = nil end elseif char == '{' then if not key then key, pos = Utils.json2table(str, pos, to) else result[key], pos = Utils.json2table(str, pos, to) key = nil end elseif char == '}' then return result, pos elseif (char == 'f' or char == 'F') then result[key], pos = json2false(str, pos, to) key = nil elseif (char == 't' or char == 'T') then result[key], pos = json2true(str, pos, to) key = nil elseif (char == 'n') then result[key], pos = json2null(str, pos, to) key = nil elseif (char == 'N') then result[key], pos = json2nan(str, pos, to) key = nil elseif numberchars[char] then if not key then key, pos = json2number(str, pos, to) else result[key], pos = json2number(str, pos, to) key = nil end end pos = pos + 1 end end --json格式中表示字符串不能使用单引号 local jsonfuncs = { ['\"'] = json2string, ['['] = json2array, ['{'] = Utils.json2table, ['f'] = json2false, ['F'] = json2false, ['t'] = json2true, ['T'] = json2true, } function Utils.json2lua(str) local char = string.sub(str, 1, 1) local func = jsonfuncs[char] if func then return func(str, 1, string.len(str)) end if numberchars[char] then return json2number(str, 1, string.len(str)) end end function Utils.table2json(tab) local str = "{" for k, v in pairs(tab) do if type(v) == "string" then str = str .. string2json(k, v) elseif type(v) == "number" then str = str .. number2json(k, v) elseif type(v) == "boolean" then str = str .. boolean2json(k, v) elseif type(v) == "table" then str = str .. table2json(k, v) end end str = string.sub(str, 1, string.len(str) - 1) return str .. "}" end ---------------------------------------------------------------------------------- -- Lua-Table 与 string / json 转换 function Main() local str0 = '{[1]=2,["name"]="dong"}' print("source-table",str0) local table1 = Utils.string2table(str0) local jsonstr1 = Utils.table2json(table1) print("table2json",jsonstr1) local table2 = Utils.json2table(jsonstr1) local str2 = Utils.table2string(table2,false) print("table2string",str2) end Main() 5.在线运行结果…

6.参考/在线工具:

参考在线工具