What is the difference between an unsigned short and a USHORT?

Question

What is the difference between USHORT and an unsigned short and when would you use each?

Solution 1

USHORT is a macro which is not part of the official C++ language (it's probably defined or typedef'ed somewhere). unsigned short is an official type defined by the C++ language as an integer that can at least hold numbers between 0 and 65535.

Use unsigned short and your code will be portable - don't use USHORT unless you company's coding standard requires it.

Solution 2

unsigned short is a standard C++ expression and USHORT is not. The precise definition can be found in the Wikipedia article Integer (computer science).

Sometimes, we typedef unsigned short USHORT in the header. Then USHORT can be used as well as unsigned short.

Comments

[Seth Carnegie]

Note that a typedef is not a macro.

[Stas Jaro]

i was looking at some sample code here:cplusplus.com/forum/lounge/17053 in the first code block. Could you take a look and see if you can figure out why they use it?

[Cheers and hth. - Alf]

@stas: it's just a Microsoft'ism, something done without any other reason than that other's doing it. It's about the same as the C'ism of writing void foo(void), when in C++ there is no point to the second void, the one in the argument list. Or the Javaism of writing double getSin(), when in C++ the get` has no purpose and is just visual noise. Cheers,

[Adrian Cornish]

@stas Looks like Microsoft C++ to me - this is a particular style adopted by the Windows guys and the Microsoft compiler defines those types. If you are working in code like this - it is usually conventional to follow the style of existing code.