Question

Simple code indeed :

int number = int.MaxValue;
    number = number+1;
Console.WriteLine(number);

Questions :

1) there’s should be overflowException. there isn’t. why is that?

2) Does the number -2147483648 indicates something about :

• ) how many bytes is beyond limit size ?

• ) if i see -2147483648 , How can I know ( if there wasnt an exception) – if this number came from exception ? – must I wrap it with Try Catch ?

p.s. when i wrote :

int number = int.MinValue;
    number = number-1;
Console.WriteLine(--number);

I got : 2147483647 (still no exception).

Answer 1

There’s should be overflowException. there isn’t. why is that?

By default, C# doesn’t do overflow checking. You can enable it for a whole assembly (in the “Advanced” bit of the build tab in VS, or /checked+ from the command line) or for a block/expression using the checked keyword

For the second part of your question, -2147483648 is just int.MinValue – signed integers do that, rolling from a very large positive number to a very large negative number.

For example, if you use sbyte (the signed byte type):

sbyte number = 127; // sbyte.MaxValue
number++;
Console.WriteLine(number); // Prints -128

There’s nothing funny going on here – it’s just normal 2s complement overflow.

Or using byte (unsigned)

byte number = 255; // byte.MaxValue
number++;
Console.WriteLine(number); // Prints 0