'itoa': The POSIX name for this item is deprecated

Question

I'm trying to convert an int into a string by doing this:

int id = 12689;
char snum[MAX];
itoa(id, snum, 10);

I get the following error:

'itoa': The POSIX name for this item is deprecated. Instead, use the ISO C and C++ conformant name: _itoa.

Possible duplicate of [How to convert an int to string in C](https://stackoverflow.com/questions/8257714/how-to-convert-an-int-to-string-in-c) — J...S, Oct 24 '17 at 17:22
Regardless of what Visual Studio tells you, there's *no* standard function named `itoa` or `_itoa`. Unless you are looking for something fancy, `snprintf()` should be good enough. — P.P, Oct 24 '17 at 17:25
Then use `#define _CRT_NONSTDC_NO_DEPRECATE` before including header files. — machine_1, Oct 24 '17 at 17:26

score 12 · Answer 1 · answered Oct 24 '17 at 17:25

That is MSVC doing that to you. If you add the following line before any library #includes

#define _CRT_NONSTDC_NO_DEPRECATE

the warning is suppressed, similar for many other functions too.

Moreover if you add these two lines as well, MSVC will stop telling you to use scanf_s instead of the standard function scanf (and others).

#define _CRT_SECURE_NO_WARNINGS
#define _CRT_SECURE_NO_DEPRECATE

Edwin Buck · Answer 2 · 2017-10-24T17:37:31.913

4

Please use snprintf, it is more portable than itoa.

char buffer[10];
int value = 234452;
snprintf(buffer, 10, "%d", value);

itoa is not part of standard C, nor is it part of standard C++; but, a lot of compilers and associated libraries support it.

edited Oct 24 '17 at 17:37

answered Oct 24 '17 at 17:31

Edwin Buck

69,361
7
100
138

The comment to rename it is just to bring the function name in line with C / C++'s naming conventions with regards to proceeding underscores `_itoa` preferred over `itoa`; but, in either case, the existence of a `itoa` function in either case is not standard C, even if it is common. It is compiler dependent, and the kind of code that needs rewritten to make porting your application easier. – Edwin Buck Oct 24 '17 at 17:41

score 1 · Answer 3 · answered Oct 24 '17 at 17:35

1

There has never been a standard itoa function in C standard library. So, trying to use it is not a good idea in any case. In C you have functions from sprintf family that will happily perform that conversion for you.

answered Oct 24 '17 at 17:35

AnT stands with Russia

312,472
42
525
765

'itoa': The POSIX name for this item is deprecated

3 Answers3