What C++ pitfalls should I avoid? [closed]

Answer 1

Always check a pointer before you dereference it. In C, you could usually count on a crash at the point where you dereference a bad pointer; in C++, you can create an invalid reference which will crash at a spot far removed from the source of the problem.

class SomeClass
{
    ...
    void DoSomething()
    {
        ++counter;    // crash here!
    }
    int counter;
};

void Foo(SomeClass & ref)
{
    ...
    ref.DoSomething();    // if DoSomething is virtual, you might crash here
    ...
}

void Bar(SomeClass * ptr)
{
    Foo(*ptr);    // if ptr is NULL, you have created an invalid reference
                  // which probably WILL NOT crash here
}