将整数值转换为字符串

Question

下面是将整数值编码为ASCII字符串的代码.它是用Python编写的,从我的测试中可以正常工作.

def encode(value):
    code = ''
    while value%254 != value:
       code = code + chr(value%254)
       value = value/254
    code = code + chr(value)
    return code

def decode(code):
    value = 0
    length = len(code)
    for i in range(0,  length):
        print code[i]
        value = value * 254 + ord(code[length-1-i])
    return value


code = encode(123456567)
print code

print decode(code)

但是,当我在Lua中尝试相同的实现时,编码和解码的值不匹配.这是我的Lua版本:

function encode(value)
    code = ''
    while value%254 ~= value do

        code = code .. string.char(value%254)
        value = value/254
    end
    code = code .. string.char(value)
    return code
end

function decode(code)
    value = 0
    code = string.reverse(code)
    for i=1, #code do
        local c = code:sub(i,i)
            print(c)
            value = value*254 + string.byte(c) 
    end
    return value
end

code = encode(2555456)

print(decode(code))

请注意,我正在尝试使用mod 254,以便我可以使用255作为分隔符.

Answer 1

1. 使用local时,你正在创建具有类似名称的变量(例如,code和value在你的代码).
2. 使用时value = value / 254,您只需要取除除法的整数部分而不是整数.

因此:

function encode(value)
    local code = ''
    while value % 254 ~= value do
        code = code .. string.char( value % 254 )
        value = math.floor( value / 254 )
    end
    code = code .. string.char( value )
    return code
end

function decode(code)
    local value = 0
    code = code:reverse()
    for i = 1, #code do
        local c = code:sub( i, i )
        value = value * 254 + c:byte()
    end
    return value
end