Lua 进制转换总结

刚好遇到一些数据上的转换，思考一番相关实现，总结一下作为笔记记录下来。
希望对你也有帮助。

16进制字符串为10进制

> print(tonumber("12345678", 16))
305419896

十进制转二进制

function dec2bin(n)
    local t = {}
      for i=31,0,-1 do
        t[#t+1] = math.floor(n / 2^i)
        n = n % 2^i
      end
      return table.concat(t)
    end

实现常规转换的所有功能

参考Lua 中 number 转换各种进制，以及string串转number

-- 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

--Test
local num = 10086

print("---- dec convert to x ----
")
local text1 = ConvertDec2X(num, 10)
local text2 = ConvertDec2X(num, 2)
local text3 = ConvertDec2X(num, 8)
local text4 = ConvertDec2X(num, 16)
local text5 = ConvertDec2X(num, 14)
print(string.format("dec %d to dec %s", num, text1))
print(string.format("dec %d to bin %s", num, text2))
print(string.format("dec %d to Oct %s", num, text3))
print(string.format("dec %d to Hex %s", num, text4))
print(string.format("dec %d to 14  %s", num, text5))


print("
---- string to num ----
")
local num1 = ConvertStr2Dec(text1, 10)
local num2 = ConvertStr2Dec(text2, 2)
local num3 = ConvertStr2Dec(text3, 8)
local num4 = ConvertStr2Dec(text4, 16)
local num5 = ConvertStr2Dec(text5, 14)
print(string.format("dec:%s to dec %d", text1, num1))
print(string.format("bin:%s to dec %d", text2, num2))
print(string.format("Oct:%s to dec %d", text3, num3))
print(string.format("Hex:%s to dec %d", text4, num4))
print(string.format("14:%s to dec %d", text5, num5))  

---- dec convert to x ----

dec 10086 to dec 10086
dec 10086 to bin 10011101100110
dec 10086 to Oct 23546
dec 10086 to Hex 2766
dec 10086 to 14  3966

---- string to num ----

dec:10086 to dec 10086
bin:10011101100110 to dec 10086
Oct:23546 to dec 10086
Hex:2766 to dec 10086
14:3966 to dec 10086