C # Difficulty one by one (7): Checked and unchecked

C # By default, if the value of a constant expression exceeds the maximum value of the target type, a compilation error will result.

If the target data type cannot hold data from a very few expressions, the data is truncated when it is assigned.

Class Program {static void Main (string[] args) {int n = Int. maxvalue;//n=2147483647 n = n + 1; System.Console.WriteLine (n); } }

At this point the available memory stores data to interpret, before int. MaxValue in memory is 32 bit 1, since adding 1 to 32 bit 0, at this time 0 is considered to be a minus sign, so it will get-2147483648.

Placing the above code in the checked block will cause the System.OverflowException type to be thrown.

Class Program {static void Main (string[] args) {checked {int m = Int. MaxValue; m = m + 1; System.Console.WriteLine (m); } } }

A variable in C # that is placed in a checked block throws an exception if the assignment of an overflow occurs at run time.

The unchecked is used to cancel overflow checking of integer arithmetic operations and conversions.

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