Convert a hexstring to byte in C++

Question

I have a Hexadecimal-String looking like this:

char hexString = "1a";

and i want to convert it to a BYTE, so that it looks like this:

BYTE Anything[0x10] = { 0x1a };

after the converion. i need to do this for 16 strings so that i have sth looking like this at the end

BYTE Anything[0x10] = { hexToByte(hexString1), hexToByte(hexString2), 16 times };

any idea, because i have no clue on how to do this!

Just like with decimals: repeated addition and multiplication, but multiplying with 16 instead of 10. If you want to do it by hand. (Note that `0x1a` is the same as `26`.) — molbdnilo, Dec 19 '15 at 13:44
[`std::stoul`](http://en.cppreference.com/w/cpp/string/basic_string/stoul) — Brian Rodriguez, Dec 19 '15 at 13:45

score 1 · Accepted Answer · answered Dec 19 '15 at 14:02

1

BYTE Anything[0x10] = {
    (BYTE)std::stoul(hexString1, nullptr, 16),
    (BYTE)std::stoul(hexString2, nullptr, 16), ... };

answered Dec 19 '15 at 14:02

Riad Baghbanli

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score 0 · Answer 2 · answered Dec 19 '15 at 14:31

There's only 256 values.... plenty small enough to look for in an array.

int hexToByte(const char* strHex)
{
   char* array[] = {"00", "01", "02", "03", "04", "05", "06", "07",
                    "08", "09", "0A", "0B", "0C", "0D", "0E", "0F",
                    "10", "11", "12", "13", "14", "15", "16", "17",
                    "18", "19", "1A", "1B", "1C", "1D", "1E", "1F"
                   /* Fill in the rest, up to FF */};

    int i;              
    for(i=0; strcmp(strHex,array[i]); ++i) ;

    return i;
}

Convert a hexstring to byte in C++

2 Answers2