Question

I have the following code.

#include "math.h" // for sqrt() function
#include <iostream>
using namespace std;

int main()
{
    cout << "Enter a number: ";
    double dX;
    cin >> dX;

    try // Look for exceptions that occur within try block and route to attached catch block(s)
    {
        // If the user entered a negative number, this is an error condition
        if (dX < 0.0)
            throw "Can not take sqrt of negative number"; // throw exception of type char*

        // Otherwise, print the answer
        cout << "The sqrt of " << dX << " is " << sqrt(dX) << endl;
    }
    catch (char* strException) // catch exceptions of type char*
    {
        cerr << "Error: " << strException << endl;
    }
}

After i run the program, i input a negative number and expected the catch handler to execute and output Error: Can not take sqrt of negative number. Instead the program terminated with the following message

Enter a number : -9
terminate called after throwing an instance of 'char const*'
Aborted

Why was my exception not caught in the catch handler?

Answer 1

You have to add const:

catch (char const * strException) // catch exceptions of type char*

In fact you are throwing char const *, but expect mutable char *, which does not match this way (it does the opposite).