Checked and Unchecked

C# statements executes in either checked or unchecked context. In a checked context, arithmetic overflow raises an exception. In an unchecked context, arithmetic overflow is ignored and the result is truncated.

short m = 32767;   
short n = 32767;
int result1 =  checked((short)(m + n));   //will throw an OverflowException
int result2 =  unchecked((short)(m + n)); // will return -2

If neither of these are specified then the default context will rely on other factors, such as compiler options.