C++ standard alternative to itoa() to convert int to base 10 char*

Question

To convert an integer to base 10 char*

std::itoa(ConCounter, ID, 10);

ConCounter is an integer, ID is a char*, and 10 is the base

It says that iota is not a member of std and without std it's not declared. I know it's a nonstandard function but I included all the libraries for it and it still doesn't see it.

What is a way to do the above? Any quick one liners? I've tried the following;

std::to_string //it's not declared for me when using mingw, it doesn't exist.
snprintf/sprintf //should work but it gives me the "invalid conversion from 'int' to 'char *'"    error
std::stoi //has same problem as iota

`to_string` is a) in C++11 and b) fixed in newer versions of MinGW. — chris, Nov 17 '13 at 18:33
@Chris which newer version ? [This](http://en.cppreference.com/w/cpp/string/basic_string/to_string) won't compile on MingW g++ (GCC) 4.8.1 — P0W, Nov 17 '13 at 18:38
@P0W, I seem to recall it being fixed in the main releases, but it definitely works fine with MinGWBuilds 4.8.1. — chris, Nov 17 '13 at 18:47
@P0W, Actually, it might be that MinGWBuilds just applies the patch for you. Here you go: http://stackoverflow.com/a/12975602/962089 — chris, Nov 17 '13 at 19:00

Bruce Dean · Answer 1 · 2013-11-17T18:46:52.800

6

Try this:

#include <sstream>

int i = // your number
std::ostringstream digit;
digit<<i;
std::string numberString(digit.str());

edited Nov 17 '13 at 18:46

answered Nov 17 '13 at 18:34

Bruce Dean

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I added this and I get a "invalid conversion from 'constant char*' to 'char*'" error – nurtul Nov 17 '13 at 18:43
It is because I removed the string part and just did ID = digit.str().c_str(); Which is why I was getting the error. – nurtul Nov 17 '13 at 18:53

score 1 · Accepted Answer · answered Nov 17 '13 at 18:45

1

I recommend using roybatty's answer, but I think sprintf should work too. I think when you used it you forgot the format string. It should be:

char buf[16];
std::snprintf(buf, sizeof(buf), "%d", integer);

answered Nov 17 '13 at 18:45

uk4321

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Everywhere I looked I never was told of the "sizeof(--)" part. It seems that part makes it work. Thank you! – nurtul Nov 17 '13 at 18:49
@nurtul you need it if you use `snprintf`, you don't if you use `sprintf`. – uk4321 Nov 17 '13 at 18:50

score 0 · Answer 3 · answered Nov 17 '13 at 18:37

0

There is also "strtol" function : http://www.cplusplus.com/reference/cstdlib/strtol/

answered Nov 17 '13 at 18:37

Denis Gladkiy

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`strol` does the opposite than what was wanted – Walter Nov 17 '13 at 18:38
Oh, sorry %) A thought it was "atoi" in the question. – Denis Gladkiy Nov 19 '13 at 15:58

C++ standard alternative to itoa() to convert int to base 10 char*

3 Answers3