Question

What I need to do is the following.

const char *arrayHex[4];
for( int i = 0; i < 5; i++ )
{    
cin << uHex;
arrayHex[i] = uHex;
}

But I need the members of arrayHex to be hex escaped with \x. How might I go about doing that?

This was really vaguely worded, edit to fix(hopefully)

If the input is 41, I want the result when printed to be “A”, as if the value was “\x41”

Answer 1

#include <iostream>
#include <string>
#include <cstdlib> // for strtol()
#include <cstdio>  // for printf()
#define countof(array) (sizeof(array)/sizeof(array[0]))

int main()
{
    std::string uHex;
    long arrayValues[4];
    for( int i = 0; i < countof(arrayValues); ++i )
    {
        std::cin >> uHex;
        char* end;
        arrayValues[i] = std::strtol(uHex.c_str(), &end, 16);
        // At this point, we expect end to be pointing at the '\0'
        // (the C-string nul terminator).  If it's not, then we have
        // invalid chars in our input, and arrayValues[i] is bogus.
        if (*end != '\0')
        {
           std::cout << "Invalid characters: \"" << uHex << "\" (please try again)\n";
           --i; // compensate for the ++i above to re-try this again
        }
    }

    for( int i = 0; i < countof(arrayValues); ++i )
    {
        std::cout << i << " --> " << arrayValues[i] << " --> "
                  << static_cast<char>(arrayValues[i]) << '\n';
//      std::printf("%d --> %d --> %c\n", i, arrayValues[i], arrayValues[i]);
    }
}

Note that I’m printing the exact same output both ways: with cout or with printf(). Personally I like printf() not because that’s what I learned first, but because printf() formatted output is significantly more expressive (for MOST built-in types) with less verbosity than cout, even though cout is more flexible because you can create cout output functions for user-defined types. But if your compiler doesn’t do printf()/scanf() format-parameter type checking (GCC does, if you enable it), then you can easily create some interesting & confusing output with mismatched types, and create nice non-deterministic SEGV generators quite easily by specifying less args than your format string indicates.