Numerical to ASCII

[dansnyderECE]

I have a vector full of decimal values and I want to convert each element of the vector to ASCII represented strings (or char arrays). How do I do this? Each element of the array is 8 hex bits long and has been converted to it's decimal representation. So...

HEX(41424344) = DEC(1094861636) = ASCII('A','B','C','D')

I have the HEX to DEC part down fine but I can't quite figure out how to do the second part. I've tried using reinterpret_cast with many issues. Any simple solutions to this problem?

I feel like I can't make a conversion from my DEC stage to ASCII correctly because its bits 0 and 1 of the HEX that give char(0) and so on. With the dec representation there isn't a straightforward conversion is there?

[daviddoria]

You may also try posting this in the C forum if you don't have any luck here.

[NathanOliver]

Well ASCII characters run from 0-255 so any number between 0 and 255 will convert right to an ASCII value

int number = 48;
char character = number; // character is now '0'

Numbers larger than 255 should wrap around but you can always use the % operator

int number = 1068
char character = number % 255; // character is now '0'

If this isn't what your looking for let me know.

[dansnyderECE]

That's a useful way of using the mod operator. I can definitely use this. So if I wanted to convert, say... 1234344356355 to a string, how would I do it? For simplicity we can just have like, char character1, char character2, etc. Would I mod number, get character1, subtract 225 from number, mod 225 again to get character2?

[daviddoria]

Just push the big number into a stringstream and then read it out as a string:

std::stringstream ss;
int number = 12345;
ss << number;
std::string yourString;
ss >> yourString;

[dansnyderECE]

When I try using a stringstream I get the following error:

error: aggregate ‘std::stringstream ss’ has incomplete type and cannot be defined

I'm not familiar with using this class. Is there something other than <string> i need to include ot use this?

Nevermind, i included <sstream>

[daviddoria]

Yes, #include <sstream>

[dansnyderECE]

Actually, this doesn't do the conversion for me as far as I can see. It converts 12345 into "12345". Im looking to go: 126 into "ABC"

[NathanOliver]

Do you mean 123 to abc?

[dansnyderECE]

Well, actually, what I want to do is take HEX( 12,ab,17,4a ) and turn it into string("abcd") (the conversion isn't correct, I'm just giving an example.)

[NathanOliver]

if you want to convert a number to a letter that you take that number plus 'A' and that will give to the letter.

int number = 4
char ch = number + 'A'; // ch is now 'E'

doing this over an array with each element being a single digit is pretty straight forward but to go from 526 to FCG is a little more complex. you will need to % 10 to get the last digit of the the number than convert it. then you /= 10 to get rid of the last digit and then keep going until you have all of the digits. This does present the problem that you will only get A-J as you letters.

[dansnyderECE]

Although somewhat unwieldy I think that it may work out just fine to take my 8 bit hex word (keep in mind that this is actually a string), convert the first 2 characters to decimal, and then type cast it, store that in my string, repeat and iterate through vector elements until I find "00". That way I won't be limited to specific characters (keep in mind that I will more than likely have to open stdout and stdin using this mechanism.)

[daviddoria]

Instead of dividing by 10, you can also do the stringstream thing to get the number into an std::string. Then you can access individual elements (numbers) with simply yourString[i] . You can do the conversion with +'A', then put humpty dumpty back together again.

[dansnyderECE]

Okay, so I have it figured out sortof using a combination of methods suggested by many people. Here's what I have so far:

string filename;
    int conversion;
    int flag = 0;
    int k=999;//(top->a0)-1;
    while (flag==0)
    {
        k+=1;
        for (int i=0; i<=3; i++)
        {
            conversion = hexCharValue(tempInstructionMemory[k][i*2])<<(4*1);
            conversion += hexCharValue(tempInstructionMemory[k][(i*2)+1])<<(4*0);
            if (conversion==0)
            {
                flag = 1;
                break;
            }
            filename+=(char)conversion;
        }
    }

Is there a more concise way of doing this same thing? I have a tendency to write very wasteful code.

[tesuji]

I have a vector full of decimal values and I want to convert each element of the vector to ASCII represented strings (or char arrays). How do I do this? Each element of the array is 8 hex bits long and has been converted to it's decimal representation. So...

HEX(41424344) = DEC(1094861636) = ASCII('A','B','C','D')

I have the HEX to DEC part down fine but I can't quite figure out how to do the second part. I've tried using reinterpret_cast with many issues. Any simple solutions to this problem?

I feel like I can't make a conversion from my DEC stage to ASCII correctly because its bits 0 and 1 of the HEX that give char(0) and so on. With the dec representation there isn't a straightforward conversion is there?

Hi
If I understand you correctly, there are hexadecimal numbers (HEX(41424344)) given where each of them consists of 4 double-digit hex numbers. As for your example, unsigned int N = 0x41424344. Obviously you want to separate this 32-bit number into its 4 double-digit hex numbers 0x41, 0x42, 0x43, 0x44. This can easily be done by masking out each double-digit number and shifting the result to its lower right position to get the ordinal number for ASCII coding, for example:

unsigned hex = 0x41424344, mas = 0xff000000; char cha[4];
int j=0; while(hex>0){cha[j]=(hex&mas)>>24;j++;hex<<=8;}
for (j=0;j<4;j++) cout << cha[j] << "  "; //output: A  B  C  D

I thing your question should have been better posted to C forum for getting faster result.

-- tesu

[dansnyderECE]

That's another interesting way of doing this. I like using logic operations as much as possible so I'll use this eventually I'm sure. Why is this kind of question better suited for the C forum? (just out of curiosity.)

[daviddoria]

I just think people here are typically more interested in STL ("new") c++ and that typically has nothing to do with hex and shift operators, etc. The C guys seem to like that stuff more :)