_ltoa, _ltow

Visual Studio 6.0

Convert a long integer to a string.

char *_ltoa( long value, char *string, int radix );

wchar_t *_ltow( long value, wchar_t *string, int radix );

Routine Required Header Compatibility
_ltoa <stdlib.h> Win 95, Win NT
_ltow <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


The _ltoa function converts the digits of value to a null-terminated character string and stores the result (up to 33 bytes) in string. The radix argument specifies the base of value, which must be in the range 2 – 36. If radix equals 10 and value is negative, the first character of the stored string is the minus sign (–). _ltow is a wide-character version of _ltoa; the second argument and return value of _ltow are wide-character strings. Each of these functions is Microsoft-specific.

Generic-Text Routine Mappings

TCHAR.H Routine _UNICODE & _MBCS Not Defined _MBCS Defined _UNICODE Defined
_ltot _ltoa _ltoa _ltow


/* 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   _itoa, _ultoa