C#中的checked和unchecked

C#中checked和unchecked关键字

checked

在checked代码段中，如果里面执行的是比较危险的代码，则会引发相关异常或者错误，例如:

static void Main(string[] args)
{
    checked
    {
        int n = int.MaxValue;
        Console.WriteLine(n+1);
    }
}

Unhandled exception. System.OverflowException: Arithmetic operation resulted in an overflow.
   at DemoProject.Program.Main(String[] args) in C:\Users\Yihao\Desktop\FZ\DemoProject\DemoProject\Program.cs:line 12

Process finished with exit code -532,462,766.

checked块的代码在运行时发生赋值溢出将引发异常。

unchecked

C#还提支持unchecked块来强制不进行溢出检查，块中溢出的赋值将不会引发异常，例如：

static void Main(string[] args)
{
    unchecked
    {
        int n = int.MaxValue;
        Console.WriteLine(n+1);
    }
}

-2147483648

Process finished with exit code 0.