c# - 为什么 int.MaxValue - int.MinValue = -1？

Question

据我了解，这应该会给你一个溢出错误，当我这样写时:

public static void Main()
{

    Console.WriteLine(int.MaxValue - int.MinValue);
}

它确实给我一个溢出错误。

但是:

public static void Main()
{

    Console.WriteLine(test());
}

public static Int32 test(int minimum = int.MinValue, int maximum = int.MaxValue)
{
    return maximum - minimum;
}

将输出-1 为什么要这样做？它应该抛出错误，因为它显然是溢出!

Answer 1

int.MaxValue - int.MinValue = int 无法保存的值。因此，数字回绕到 -1。

就像 2147483647-(-2147483648) = 4294967295 不是 int

Int32.MinValue Field

The value of this constant is -2,147,483,648; that is, hexadecimal 0x80000000.

和Int32.MaxValue Field

The value of this constant is 2,147,483,647; that is, hexadecimal 0x7FFFFFFF.

来自 MSDN

When integer overflow occurs, what happens depends on the execution context, which can be checked or unchecked. In a checked context, an OverflowException is thrown. In an unchecked context, the most significant bits of the result are discarded and execution continues. Thus, C# gives you the choice of handling or ignoring overflow.