Difficulty with constructors for complex number class. - constructor

Question

I am working on a programming assignment. The assignment is to create a class for complex numbers, representing the numbers as two variables of type double. I am supposed to overload the +, -, *, <<, and >> symbols. I am struggling with this assignment. My code is all over the place, and each change I make increases the number of compiler errors. As many recommendations on what I am doing wrong and ways to improve as possible would be appreciated. Thank you in advance. My discombobulated code is below:
class Complex
{
public:
Complex();
Complex(double& realNumber, double& imaginaryNumber);
Complex(double realPart);
void input();
void output();
double getReal() const;
double getImaginary() const;
friend const Complex operator +(const Complex& num1, const Complex& num2);
friend const Complex operator -(const Complex& num1, const Complex& num2);
const Complex operator *(const Complex& num1, const Complex& num2);
bool Complex operator ==(const Complex& num1, const Complex& num2);
private:
double real, imaginary;
const Complex i(0, 1);
};
Complex::Complex(double& realPart);
Complex::Complex(double& realNumber, double& imaginaryNumber) : 0(realNumber),0*i(imaginaryNumber)
const Complex operator +(const Complex& num1, const Complex& num2);
const Complex operator -(const Complex& num1, const Complex& num2);
const Complex operator *(const Complex& num1, const Complex& num2);
bool Complex operator ==(const Complex& num1, const Complex& num2);
//------------------------------------------------
#include <iostream>
#include <cstdlib>
#include <cmath>
using namespace std;
int main()
{
Complex number1, number2, number3;
const double i = sqrt(-1);
Complex::Complex(double& realPart) : realPart(realPart + 0*i)
Complex::Complex(double& realNumber, double& imaginaryNumber) : 0(realNumber),0*i(imaginaryNumber)
const Complex operator +(const Complex& num1, const Complex& num2)
{
Complex num3;
num3.real = num1.getReal() + num2.getReal();
num3.imaginary = (num1.getImaginary() + num2.getImaginary());
return number3;
}
const Complex operator -(const Complex& num1, const Complex& num2)
{
Complex num3;
num3.real = num1.getReal() - num2.getReal();
num3.imaginary = (num1.getImaginary() - num2.getImaginary());
return number3;
}
const Complex operator *(const Complex& num1, const Complex& num2)
{
complex num3;
num3.real =(num1.getReal * num2.getReal() - num1.getImaginary() * num2.getImaginary()) ;
num3.imaginary = (num1.getReal() * num2.getImaginary() + num1.getImaginary() *num2.getReal);
return number3;
}
bool Complex operator ==(const Complex& num1, const Complex& num2)
{
return ( (num1.getReal() == num2.getReal() ) && (num1.getImaginary() == num2.getImaginary() ));
}
number1.input();
cout<<"Now please repeat with the second imaginary number: \n"<<endl;
number2.input();
if (number1 == number2)
{
cout<<number1<<" is equal to "<<number2<<endl;
}
else if (number1 > number2)
{
cout<<number1<<"is greater than "<<number2<<endl;
}
else
{
cout<<number1<<"is less than "<<number2<<endl;
};
cout<<number1<<" + "<<number2<<" = "<<number1+number2<<endl;
cout<<number1<<" - "<<number2<<" = "<<number1 - number2<<endl;
cout<<number1<<" * "<<number2<<" = "<<number1*number2<<endl;
};
//----------------------------------------
void Complex::input()
{
cout<<"Enter the real number of your complex number: "<<endl;
cin>>real;
cout<<"Enter the imaginary number (the numeral before the 'i') of your complex number" <<endl;
cin>>imaginary;
};
//void Complex::output()

Answer 1

temp.cpp:20:70: error: ‘const Complex Complex::operator*(const Complex&, const Complex&)’ must take either zero or one argument
const Complex operator *(const Complex& num1, const Complex& num2);
that's pretty unambiguous as far as errors go: the 'binary' (or two argument) operators are not class members - and you declare the 'binary' operators correctly as friends and again correctly define them in global scope later on in the code;
the 'unary' versions must be class members and the "other" object involved in the operation is 'this', as in, add 'this' complex number and the given one and return the result.
the '*' operator is special in the sense that it has a no-arguments version that is used for something else (...)
I know compiler errors can be overwhelming; so comment out code (like, all but your class declaration) and work your way through each error; then uncomment a bit more etc. Compile early, compile often. C++ freaking out over a misplaced semi-colon is easier to catch that way.