c++异常处理

标准异常类

#include "stdafx.h"
#include "iostream"
#include "Vector"
#include <stdexcept>

using namespace std;
int _tmain(int argc, _TCHAR* argv[])
{
  vector <int> nums(10,1);
  try
  {
    cout << nums.at(1) << endl;
    cout << nums.at(11) << endl;  //  at()访问越界元素时会抛出out_of_range异常
    cout << nums.at(2) << endl;
  }
  catch (out_of_range e)
  {
    cout << e.what() << endl;    // what() 输出异常信息
  }
  cout << nums.at(3) << endl;

  return 0;
}

自定义的异常

class CException
{
public:
  string msg;
  CException(string errmsg):msg(errmsg){}
};

double Devide(double num1, double num2)
{
  if (num2 == 0)
  {
    throw CException("devide by zero"); // 抛出自定义异常
  }
  return num1 / num2;
}

int _tmain(int argc, _TCHAR* argv[])
{
  try
  {
    cout << "result=" << Devide(16, 0) << endl;
  }
  catch (CException e)
  {
    cout << e.msg.c_str() << endl;
  }

  return 0;
}