c# checked关键字

checked 关键字用于对整型算术运算和转换显式启用溢出检查。

此示例演示如何使用 checked 启用运行时溢出检查。

C#

    class OverFlowTest    {        // Set maxIntValue to the maximum value for integers.        static int maxIntValue = 2147483647;        // Using a checked expression.        static int CheckedMethod()        {            int z = 0;            try            {                // The following line raises an exception because it is checked.                z = checked(maxIntValue + 10);            }            catch (System.OverflowException e)            {                // The following line displays information about the error.                Console.WriteLine("CHECKED and CAUGHT:  " + e.ToString());            }            // The value of z is still 0.            return z;        }        // Using an unchecked expression.        static int UncheckedMethod()        {            int z = 0;            try            {                // The following calculation is unchecked and will not                 // raise an exception.                z = maxIntValue + 10;            }            catch (System.OverflowException e)            {                // The following line will not be executed.                Console.WriteLine("UNCHECKED and CAUGHT:  " + e.ToString());            }            // Because of the undetected overflow, the sum of 2147483647 + 10 is             // returned as -2147483639.            return z;        }        static void Main()        {            Console.WriteLine("\nCHECKED output value is: {0}",                              CheckedMethod());            Console.WriteLine("UNCHECKED output value is: {0}",                              UncheckedMethod());        }        /*       Output:       CHECKED and CAUGHT:  System.OverflowException: Arithmetic operation resulted       in an overflow.          at ConsoleApplication1.OverFlowTest.CheckedMethod()        CHECKED output value is: 0       UNCHECKED output value is: -2147483639     */    }