c++ 投掷错误

Question

I am writing a c++ code that add o node to end of a list I want to throw error when a node is already exist, it is working but whenever I call it with already exiting node I get this error. Anyone know the reason and how it is fixed?

exception terminate called after throwing an instance of 'Error'
Aborted

List& List::addnode(node p){
    node *Current=NULL;

    p.nextNode = NULL;
    p.previousNode = NULL;

    if (!firstNode) firstNode = &p;

    else Current = firstNode;
    while (Current){
            if ((*Current) == p){
                    throw NodeExist;
                    return *this;
            }
            if (!(Current->nextNode)){
                    Current->nextNode = &p;
                    p.previousNode = Current;
                    return *this;
            }
            Current = Current->nextNode;

    }

}

edit: I call it like that

try{
x.addNode(p);
x.addNode(p1);
x.addNode(p2);
x.addNode(p1);
x.addNode(p4);
}
catch(int i){
cout<<i<<endl;
}

if I erase one of the x.addNode(p1); line it work normally without an exception...

Answer 1

you don't catch and handle NodeExist anywhere. so it goes up the call chain all the way to main.

catch(int i) doesn't match NodeExist to catch that you need catch(Error e)

Answer 2

What else were you expecting?

You throw an exception, and your application is terminating with the exception. It's doing what you told it to do.

To be more specific, you're not catch ing the exception anywhere higher up the call chain in your program, so the exception is terminating the program.