C++中异常捕获

1.异常的再拋出 

#include <QCoreApplication>
#include <exception>
#include <iostream>
#include <stdlib.h>

using namespace std;

int CountTax(int salary)
{
    try
    {
        if(salary < 0)
            throw string("zero salary");

        cout << "counting tax" << endl;
    }
    catch(string s)
    {
        cout << "CountTax error : " << s << endl;
        throw; //继续抛出捕获的异常
    }

    cout << "tax counted" << endl;
    return salary * 0.15;
}

int main(int argc, char *argv[])
{
    QCoreApplication a(argc, argv);

    try
    {
        CountTax(-1);
        cout << "end of try block" << endl;
    }
    catch(string s)
    {
        cout << "&&&&&&&&&&&&&:"<< s << endl;
    }
    cout << "finished" << endl;

    return a.exec();
}

2.捕获任何异常的catch语句

#include <QCoreApplication>
#include <exception>
#include <iostream>
#include <stdlib.h>

using namespace std;

int main(int argc, char *argv[])
{
    QCoreApplication a(argc, argv);

    double m, n;
    cin >> m >> n;

    try
    {
        cout << "before dividing." << endl;
        if (n == 0.0)
            throw - 1;  //抛出整型异常
        else if(m == 0.0)
            throw - 1.0;  //拋出 double 型异常
        else
            cout << m / n << endl;

        cout << "after dividing." << endl;
    }
    catch(double d)
    {
        cout << "catch (double)" << d << endl;
    }
    catch(int d)
    {
        cout << "catch (...)" << d << endl;
    }
    cout << "finished" << endl;

    return a.exec();
}