Why isn't ~ of 6 = 1 since it flips the bits?

Question

see example below. I was either expecting it to be 1 or 249 if we account for the whole bits in the byte type.

I read the sources but I can't figure out why I am not able to grasp it.

byte num1 = 6;
byte num2 = 12;
Assert.IsTrue(~num1 == 1);
Assert.IsTrue(~num2 == 3);

Answer 1

~ operator converts type to int. If you want byte - use cast:

byte num1 = 6;
byte num2 = 12;
Console.WriteLine((byte)~num1);
Console.WriteLine((byte)~num2);