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

From:
anon <anon@no.no>
Newsgroups:
comp.lang.c++
Date:
Tue, 20 Nov 2007 16:29:32 +0100
Message-ID:
<fhuugs$s75$1@el-srv04-CHE.srvnet.eastlink.de>
Angus wrote:

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.


Sorry, it still does not compile for me.
Check this link:
http://www.parashift.com/c++-faq-lite/how-to-post.html#faq-5.8

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