Lua 中 number 转换各种进制，以及string串转number

原文地址：http://blog.csdn.net/david_dai_1108/article/details/71699449

--region : NumConvert.lua
--Date   : 2017-5-11
--Author : david

-- Bin 2
-- Oct 8
-- Dec 10
-- Hex 16

local _convertTable = {
    [0] = "0",
    [1] = "1",
    [2] = "2",
    [3] = "3",
    [4] = "4",
    [5] = "5",
    [6] = "6",
    [7] = "7",
    [8] = "8",
    [9] = "9",
    [10] = "A",
    [11] = "B",
    [12] = "C",
    [13] = "D",
    [14] = "E",
    [15] = "F",
    [16] = "G",
}

local function GetNumFromChar(char)
    for k, v in pairs(_convertTable) do
        if v == char then
            return k
        end
    end
    return 0
end

local function Convert(dec, x)

    local function fn(num, t)
        if(num < x) then
            table.insert(t, num)
        else
            fn( math.floor(num/x), t)
            table.insert(t, num%x)
        end
    end
    
    local x_t = {}
    fn(dec, x_t, x)

    return x_t
end

function ConvertDec2X(dec, x)
    local x_t = Convert(dec, x)

    local text = ""
    for k, v in ipairs(x_t) do
        text = text.._convertTable[v]
    end
    return text
end

function ConvertStr2Dec(text, x)
    local x_t = {}
    local len = string.len(text)
    local index = len
    while ( index > 0) do
        local char = string.sub(text, index, index)
        x_t[#x_t + 1] = GetNumFromChar(char)
        index = index - 1
    end

    local num = 0
    for k, v in ipairs(x_t) do
        num = num + v * math.pow(x, k - 1) 
    end
    return num
end

--endregion