class myexc : public exception
{
virtual const char * what () const throw ()
{
return “my own exception”;
}
} mye;

int main()
{
try
{

throw mye;
}

catch (exception & e)
{
cout<<e.what()<<"in main cacth ";
}
return 0;
}
other things i want to hilight that by default a function can throw all type of exception but if we want a function to not throw exception then add throw() at end of function signature like

myfun() throw()

Please add a article for this topic.

Now, if the user passes in an invalid exception, operator[] will throw an int exception.