_ultoa() — Convert Unsigned Long Integer to String
Format
#include <stdlib.h>
char *_ultoa(unsigned long value, char *string, int radix);
Note: The
_ultoa
function is supported
only for C++, not for C.Language Level
Extension
Threadsafe
Yes
Description
_ultoa
converts
the digits of the given unsigned long value to
a character string that ends with a null character and stores the
result in string. The radix argument
specifies the base of value; it must be
in the range 2 to 36.
Note: The space allocated for string must
be large enough to hold the returned string. The function can return
up to 33 bytes including the null character (\0).
Return Value
_ultoa
returns
a pointer to string. There is no error return
value.
When the string argument is NULL or the radix is
outside the range 2 to 36, errno
will be set to EINVAL.
Example
This example converts the integer
value 255 to a decimal, binary, and hexadecimal representation.
#include <stdio.h>
#include <stdlib.h>
int main(void)
{
char buffer[35];
char *p;
p = _ultoa(255UL, buffer, 10);
printf("The result of _ultoa(255) with radix of 10 is %s\n", p);
p = _ultoa(255UL, buffer, 2);
printf("The result of _ultoa(255) with radix of 2\n is %s\n", p);
p = _ultoa(255UL, buffer, 16);
printf("The result of _ultoa(255) with radix of 16 is %s\n", p);
return 0;
}
The output should be: The result of _ultoa(255) with radix of 10 is 255
The result of _ultoa(255) with radix of 2
is 11111111
The result of _ultoa(255) with radix of 16 is ff