[Cubies]

Hey guys,

I've been studying variables and started working with bytes but everytime I compile this simple code I get the error message;

Cannot implicitly convert type 'int' to 'byte'. An explicit conversion exists (are you missing a cast?)

This works perfectly with integers but why not bytes too?

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace MyFirstProject
{
class Program
{
static void Main(string[] args)
{
byte a = 1,
b = 2,
c;

c = a + b;

Console.WriteLine(c);
}
}
}

Thanks from Cubies.

[clifford]

The type of the expression a + b is int not byte, and you cannot assign a byte with an int without telling the compiler explicitly that it is intentional.

c = (byte)(a + b) ;

As ever RTFM :rolleyes:

[Cubies]

Why does it assume I'm trying to add an int value to a byte when I'm clearly multiplying two byte values together?

[jwdonahue]

Please learn to use code blocks to maintain proper code formatting.

In C#, when you add two bytes together the result is always an int. This is because you can't accurately store every result of a byte + byte operation in a byte due to potential overflow. Because C# will only implicitly convert to a larger size, you'll have to explicitly convert the result with a cast. You have three options:

c = checked( (byte)(a + b) ) ;
c = (byte)(a + b) ;
c = (byte)( (a + b) % 255 ) ;

The second unchecked variation is inherently unsafe and may not yield the results you expect. The third option also loses information and may or may not be equivalent the second.