_ultoa, _ultow
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_ultoa, _ultow

Convert an unsigned long integer to a string.

char *_ultoa(
   unsigned long value,
   char *string,
   int radix 
wchar_t *_ultow(
   unsigned long value,
   wchar_t *string,
   int radix 


Number to be converted.
String result.
Base of value.

Return Value

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


The _ultoa function converts value to a null-terminated character string and stores the result (up to 33 bytes) in string. No overflow checking is performed. radix specifies the base of value; radix must be in the range 2 – 36. _ultow is a wide-character version of _ultoa.

Generic-Text Routine Mappings

TCHAR.H routine _UNICODE & _MBCS not defined _MBCS defined _UNICODE defined
_ultot _ultoa _ultoa _ultow


Routine Required header Compatibility
_ultoa <stdlib.h> Win 98, Win Me, Win NT, Win 2000, Win XP
_ultow <stdlib.h> or <wchar.h> Win 98, Win Me, Win NT, Win 2000, Win XP

For additional compatibility information, see Compatibility in the Introduction.


All versions of the C run-time libraries.


See the example for _itoa.

See Also

Data Conversion Routines | _itoa | _ltoa | Run-Time Routines and .NET Framework Equivalents

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