C++ int -> hex

gistfile1.txt

#include <iostream>
#include <string>


// think of 'nibbles' parameter as a kind of hexidecimal version of decimal places
std::string int_to_hex(unsigned long value, int nibbles)
{
    static const char converter[] = { '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'A', 'B', 'C', 'D', 'E', 'F' };
    
    // stack allocate C style string, just enough to fit 'nibbles' amount
    char s[nibbles];
    
    // terminate C-style string
    s[nibbles] = 0;
    
    // move through as many "decimal places" as requested
    while(nibbles-- > 0)
    {
        // per place, grab the bottom most nibble out of value
        char c = converter[value & 0xF];
        // convert it to a character and store it in C-style string
        s[nibbles] = c;
        // bit shift over to grab next nibble
        value >>= 4;
    }
    
    // convert c style string to c++ style string
    return { s };
}

int main()
{
    std::cout << "hi2u: " << int_to_hex(10, 4) << std::endl;
    std::cout << "hi2u: " << int_to_hex(0x1234, 4) << std::endl;
    std::cout << "hi2u: " << int_to_hex(0x1234, 8) << std::endl;
    std::cout << "hi2u: " << int_to_hex(0xFF007F, 4) << std::endl;
}