除零之外没有被catch块捕获？ [英] division by zero is not caught by catch block?

问题描述

嗨
考虑以下代码块

Hi consider the following code block

#include<iostream>
int main()
{
    int i=0;
    try{
        int k=9/i;
    }
    catch(...)
    {
     std::cout<<"exception occurs"<<std::endl; //control should come here
    }

}

当我运行代码未处理的异常时显示并且控件没有去捕获块

为什么会这样？

when I run above code unhandled exception is shown and control doesn't go to catch block
why is it like that?

推荐答案

因为这不是C ++异常，它是浮点数，例如，请参见：如何使用try ... catch来捕获浮点错误？ [ ^ ]。

Beacuse that's not a C++ exception, it is a floating point one, see, for instance, here: "How do I use try…catch to catch floating point errors?"[^].

确实发生了 - 我刚测试过它。

It does occur - I just tested it.

int main()
    {
    int i=0;
    try{
        int k=9/i;
        }
    catch(...)
        {
        std::cout<<"exception occurs"<<std::endl; //control should come here
        }
    }

它没有出现在您的原始版本中，因为编译器查看代码，看到常量除以常量并将其优化为常量值。然后抱怨在编译时而不是运行时间除以零。

It didn't occur in your original version, because the compiler looked at the code, saw a constant divided by a constant and optimised it to a constant value. And then complained about the divide by zero at compile time instead of run time.

除以零不是C ++异常，因此try-catch块无法捕获它。



以下是一些读物：

捕获异常：除以零点数[[a href =http://stackoverflow.com/questions/6121623/catching-exception-divide-by-zerotarget =_ blanktitle =新窗口> ^ ]

C ++：捕获除零错误 [ ^ ]



如果您使用的是VC ++编译器，则可以使用结构化异常处理。这是一个例子：

Division by zero is not a C++ exception so a try-catch block cannot catch it.

Here are some readings for you:
Catching exception: divide by zero[^]
C++ : Catch a divide by zero error[^]

If you're using a VC++ compiler then you can use structured exception handling for this. Here is an example:

#include <windows.h>
#include <Excpt.h>

int main()
{
   int i = 0;
   __try
   {
      int k = 9 / i;
   }
   __except(_exception_code() == EXCEPTION_INT_DIVIDE_BY_ZERO ? EXCEPTION_EXECUTE_HANDLER : EXCEPTION_CONTINUE_SEARCH)
   {
      std::cout << "exception occurs" << std::endl; //control should come here
   }

   return 0;
}

您可以在 MSDN [ ^ ]。

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