Re: Convert decimal values to hex and put in a string

From:

Angus <anguscomber@gmail.com>

Newsgroups:

comp.lang.c++

Date:

Tue, 20 Nov 2007 06:53:06 -0800 (PST)

Message-ID:

<6398568b-c051-4cb6-9c3a-e34e1b3b3a17@y5g2000hsf.googlegroups.com>

On Nov 20, 1:01 pm, anon <a...@no.no> wrote:

Angus wrote:

Hello

I have an unsigned char[14] and I want to convert the individual array
values into hex and copy to a std::string.

The array does not always hold 14 values - but I do know the length of
the data - obviously up to 14 chars.

An example is an array of six items with decimal values: 0, 10, 228,
164, 72, 11. I want to convert these values to hex and copy to a
string. Eg 000AE4A4480B - which the astute might recognise as a MAC
address.

I tried:

unsigned char cval = 10; // A
std::strstream str;
str << std::hex << cval << std::endl;
std::cout << str.str;

But that outputs 1 for some reason.

As does this:
unsigned char cvals[6];
// populate values
str << std::hex << cvals << std::endl;
std::cout << str.str;

also outputs 1 !

How should I be doing this?

Your examples do not compile for me, therefore I have no idea how you
made them output whatever you got there.- Hide quoted text -

- Show quoted text -

I meant a std::ostringstream.

I am now doing this:

std::ostringstream strm;
for(int nMAC = 0; nMAC < MACLength; nMAC++)
{
strm << std::hex << std::setw(2) << std::setfill('0')
<< static_cast<int>(byarrMAC[nMAC]);
}

m_strMAC = strm.str();
//convert to uppercase
std::transform(m_strMAC.begin(), m_strMAC.end(), m_strMAC.begin(),
toupper);

And it works.