Last modified: July 23, 2011

Applies to: Outlook

Converts a null-terminated string of hexadecimal digits into an unsigned long integer.

Header file:


Implemented by:


Called by:

Client applications and service providers

ULONG UlFromSzHex(


[in] Pointer to the null-terminated string to be converted. The lpsz parameter must not exceed 65536 characters.

UlFromSzHex returns an unsigned long integer. If the string does not begin with at least one hexadecimal digit, zero is returned.

The UlFromSzHex function stops converting when it reaches the first character in the string that is not a hexadecimal digit. For example, given the string "5a", UlFromSzHex returns the integer value 90. Given the string "5g5h", the function returns the integer value 5. Given the string "g5h5", UlFromSzHex returns zero.

UlFromSzHex is sensitive to diacritical differences but allows both 'a' through 'f' and 'A' through 'F' for hexadecimal digits. Strings in the Unicode and DBCS formats are supported. The length limit on lpsz is in characters, not necessarily bytes.