Question

I am trying to write an operator != function that compares if two complex numbers are the same. I Have written an equal to == function which works well but I am trying to use the negation of the result.

bool ComplexNumber::operator !=(ComplexNumber a) {
    return !(this==(a));  //the == has been overloaded
}

Answer 1

return !(this==(a)); is comparing a ComplexNumber* to a ComplexNumber. Change to:

bool ComplexNumber::operator !=(const ComplexNumber& a) const {
    return !(*this == a);  //the == has been overloaded
}

Also added const qualifier to function and argument (which I changed to to a reference to avoid unnecessary copy). You will need to add const qualifier to bool ComplexNumber::operator ==() if it is not already present.