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Convert an unsigned long integer to a string. More secure versions of these functions are available; see _ultoa_s, _ultow_s.
char *_ultoa(
   unsigned long value,
   char *str,
   int radix 
);
wchar_t *_ultow(
   unsigned long value,
   wchar_t *str,
   int radix 
);
template <size_t size>
char *_ultoa(
   unsigned long value,
   char (&str)[size],
   int radix 
); // C++ only
template <size_t size>
wchar_t *_ultow(
   unsigned long value,
   wchar_t (&str)[size],
   int radix 
); // C++ only
Parameters
- value 
 Number to be converted.
- str 
 String result.
- radix 
 Base of value*.*
Return Value
Each of these functions returns a pointer to str. There is no error return.
Remarks
The _ultoa function converts value to a null-terminated character string and stores the result (up to 33 bytes) in str. 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.
| .gif) Security Note | 
|---|
| To prevent buffer overruns, ensure that the str buffer is large enough to hold the converted digits plus the trailing null-character. | 
In C++, these functions have template overloads that invoke the newer, secure counterparts of these functions. For more information, see Secure Template Overloads.
Generic-Text Routine Mappings
| TCHAR.H routine | _UNICODE & _MBCS not defined | _MBCS defined | _UNICODE defined | 
|---|---|---|---|
| _ultot | _ultoa | _ultoa | _ultow | 
Requirements
| Routine | Required header | 
|---|---|
| _ultoa | <stdlib.h> | 
| _ultow | <stdlib.h> or <wchar.h> | 
For additional compatibility information, see Compatibility in the Introduction.
Example
See the example for _itoa.