根据设计，为什么C＃编译器允许将任何float或double值除以零？

Question

By design, why does the C# compiler allows any float or double values to be divided by zero?

class Program
{
    static void Main(string[] args)
    {
        double x = 0.0 / 0;

        float y = 1f / 0;


    }
}

Answer 1

Because IEEE 754 floating-point values have special non-numeric values to deal with this:

PS Home:\> 1.0/0
Infinity
PS Home:\> 0.0/0
NaN

whereas dividing an integer by zero is always an exception (in the C# sense ¹ ), so you could just throw the exception directly.

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¹ Dividing a floating-point number by zero is also an exception but at a completely different level and many programming languages abstract this away.

Answer 2

因为浮点值具有无穷大的有效（且真正有用）表示，而任何类型的整数都没有。

Answer 3

The reason the compiler allows you to divide a float or a double by zero, is that float and double have representations on the notion of positive infinity and negative infinity (and "not a number"), so it is a meaningful thing to allow.

One oddity is that the compiler fails spot

 decimal d = 2; 
 decimal d2 = d/0M

as a divide by zero, even though it does spot it if you write the equivalent code for an integer.