Which integer is the fastest?

Choosing the right type of integer to use can have an impact on the performance of your system. I wouldn’t worry too much about this: the CLR is pretty good at optimizing your code, and the just-in-time (JIT) compiler also applies many optimizations. Let’s consider an example. Imagine that we have a for loop that iterates over a piece of code. If we have less than 255 iterations, we might be tempted to use a byte. After all, a byte is just 1 byte. If you use an integer, it will be 4 bytes. That is more memory and probably takes longer to process, right?

Wrong!

Don’t try to outsmart the compiler. It knows the system a lot better than you do.

Let me show you.

We have the following four lines of C# code:

var a = byte.MaxValue;
var b = UInt16.MaxValue;
var c = UInt32.MaxValue;
var d = UInt64.MaxValue;

We set four variables to some values. The following table describes the specifics of each type:

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