Question

Should you use Int32 in places where you know the value is not going to be higher than 32,767?

I’d like to keep memory down, hoever, using casts everywhere just to perform simple arithmetic is getting annoying.

short a = 1;

short result = a + 1; // Error

short result = (short)(a + 1); // works but looks ugly when does lots of times

What would be better for overall application performance?

Answer 1

If you are creating large arrays, then it can save a considerable amount of memory to use narrower types (less bytes), as the size of the array will be “type width” * “number of elements” + “overhead”.

However, I’m pretty sure by default that in classes and structs, they will be packed along whole word boundaries e.g. 32bit = 4bytes. A short will still be packed into a 4 byte space.

You can however, manually configure packing in structs\classes by using structure layout:

http://msdn.microsoft.com/en-us/library/system.runtime.interopservices.structlayoutattribute(VS.71).aspx

As with any performance related issue: “don’t think – measure”.

From an API perspective, it can be majorly annoying to have to keep casting from shorts to ints, etc, as you will find most APIs will use ints for example.