_itoa, _i64toa, _ui64toa, _itow, _i64tow, _ui64tow

Visual Studio 6.0

Convert an integer to a string.

char *_itoa( int value, char *string, int radix );

char *_i64toa( __int64 value, char *string, int radix );

char * _ui64toa( unsigned _int64 value, char *string, int radix );

wchar_t * _itow( int value, wchar_t *string, int radix );

wchar_t * _i64tow( __int64 value, wchar_t *string, int radix );

wchar_t * _ui64tow( unsigned __int64 value, wchar_t *string, int radix );

Routine Required Header Compatibility
_itoa <stdlib.h> Win 95, Win NT
_i64toa <stdlib.h> Win 95, Win NT
_ui64toa <stdlib.h> Win 95, Win NT
_itow <stdlib.h> Win 95, Win NT
_i64tow <stdlib.h> Win 95, Win NT
_ui64tow <stdlib.h> Win 95, Win NT

For additional compatibility information, see Compatibility in the Introduction.


LIBC.LIB Single thread static library, retail version
LIBCMT.LIB Multithread static library, retail version
MSVCRT.LIB Import library for MSVCRT.DLL, retail version

Return Value

Each of these functions returns a pointer to string. There is no error return.



Number to be converted


String result


Base of value; must be in the range 2 – 36


The _itoa, _i64toa, and _ui64toa function convert the digits of the given value argument to a null-terminated character string and stores the result (up to 33 bytes) in string. If radix equals 10 and value is negative, the first character of the stored string is the minus sign ( – ). _itow, _i64tow, and _ui64tow are wide-character versions of _itoa, _i64toa, and _ui64toa respectively.

Generic-Text Routine Mappings

TCHAR.H Routine _UNICODE & _MBCS Not Defined _MBCS Defined _UNICODE Defined
_itot _itoa _itoa _itow


/* ITOA.C: This program converts integers of various
 * sizes to strings in various radixes.

#include <stdlib.h>
#include <stdio.h>

void main( void )
   char buffer[20];
   int  i = 3445;
   long l = -344115L;
   unsigned long ul = 1234567890UL;

   _itoa( i, buffer, 10 );
   printf( "String of integer %d (radix 10): %s\n", i, buffer );
   _itoa( i, buffer, 16 );
   printf( "String of integer %d (radix 16): 0x%s\n", i, buffer );
   _itoa( i, buffer, 2  );
   printf( "String of integer %d (radix 2): %s\n", i, buffer );

   _ltoa( l, buffer, 16 );
   printf( "String of long int %ld (radix 16): 0x%s\n", l,
                                                    buffer );

   _ultoa( ul, buffer, 16 );
   printf( "String of unsigned long %lu (radix 16): 0x%s\n", ul,
                                                    buffer );


String of integer 3445 (radix 10): 3445
String of integer 3445 (radix 16): 0xd75
String of integer 3445 (radix 2): 110101110101
String of long int -344115 (radix 16): 0xfffabfcd
String of unsigned long 1234567890 (radix 16): 0x499602d2

Data Conversion Routines

See Also   _ltoa, _ultoa