运算符重载错误[重复]

这个问题在这里已有答案：

• What is an undefined reference/unresolved external symbol error and how do I fix it? 30个答案

我在这里有代码，我试图理解运算符重载，我遇到了一个错误的路障，我完全不明白 . 该错误上有3个LNK2019错误，读取未解析的外部符号 . 我想知道错误是什么以及如何解决它 . 感谢您的帮助 .

这是我的实现代码 .

ComplexNumber::ComplexNumber()
{
double complexNumberValue = 0.00;
double realNumberValue = 0.00;
}

ComplexNumber::ComplexNumber(double real, double imaginary)
{
realNumberValue = real;
complexNumberValue = imaginary;
}

ComplexNumber ComplexNumber::operator*(const ComplexNumber& rho) const
{
double newValue = realNumberValue * rho.getValue();
ComplexNumber newNumber(newValue, complexNumberValue);
return newNumber;

}

ComplexNumber ComplexNumber::operator+(const ComplexNumber& rho) const
{
double newValue = realNumberValue + rho.getValue();
ComplexNumber newNumber(newValue, complexNumberValue);
return newNumber;
}

ComplexNumber ComplexNumber::operator-(const ComplexNumber& rho) const
{
double newValue = realNumberValue - rho.getValue();
ComplexNumber newNumber(newValue, complexNumberValue);
return newNumber;
}

ComplexNumber ComplexNumber::operator/(const ComplexNumber& rho) const
{
double newValue = realNumberValue / rho.getValue();
ComplexNumber newNumber(newValue, complexNumberValue);
return newNumber;
}

ComplexNumber ComplexNumber::operator=(const ComplexNumber& rho)
{
realNumberValue = rho.realNumberValue;
return *this;
}

bool operator==(const ComplexNumber& leftOp, const ComplexNumber& rightOp)
{
    if (leftOp.getValue() == rightOp.getValue())
    {
    return true;
    }
    else
    {
    return false;
    }
}

ostream& operator<<(ostream& out, const ComplexNumber& rho)
{
out << rho.getValue();
return out;
}

这是我的驱动程序代码 .

#include "ComplexNumbers.h"

int main()
{
// Create complex numbers to do arithmentic with
ComplexNumber cm1(1, 2);
ComplexNumber cm2(1, -2);

// test addition operator
ComplexNumber cm3 = cm1 + cm2;
cout << cm3 << endl;

// test subtraction operator
ComplexNumber cm4 = cm1 - cm2;
cout << cm4 << endl;

// test multiplication operator
ComplexNumber cm5 = cm1 * cm2;
cout << cm5 << endl;

// test division operator
ComplexNumber cm6 = cm1 / cm2;
cout << cm6 << endl;

// test assignment operator
cm6 = cm5;
cout << cm6 << endl;

// test comparison operator
if (cm1 == cm2)
    cout << "\nThey are equal.\n";
else
    cout << "\nThey are not equal.";

ComplexNumber cm8(1, 2);
if (cm1 == cm8)
    cout << "\nThey are equal.\n";
else
    cout << "\nThey are not equal.";

system("PAUSE");
return 0;
}

这是请求的头文件

#include <string>
#include <iomanip>
#include <iostream>
#include <fstream>
#include <stdexcept>

using namespace std;

class ComplexNumber
{
public:
//Constructor
//Purpose: Set the value of ComplexNumber to 0
//Parameters: None
//Returns: None
ComplexNumber();

//Parameterized Constructor
//Purpose: Set the value of ComplexNumber to the parameter
//Parameters: A double, and a double
//Returns: None
ComplexNumber(double, double);

//getValue
//Purpose:Getter for complexNumberValue
//Parameters: None
//Returns: the double value of object
double getValue() const;

//plusOverload
//Purpose: Overload the + operator 
//Parameters: The ComplexNumber on the right side of the operator
//Returns: A new ComplexNumber object containing the sum
ComplexNumber operator+(const ComplexNumber&) const;

//minusOverload
//Purpose: Overload the - operator 
//Parameters: The ComplexNumber on the right side of the operator
//Returns: A new ComplexNumber object containing the difference
ComplexNumber operator-(const ComplexNumber&) const;

//multiplicationOverload
//Purpose: Overload the * operator 
//Parameters: The ComplexNumber on the right side of the operator
//Returns: A new ComplexNumber object containing the product
ComplexNumber operator*(const ComplexNumber&) const;

//divisionOverload
//Purpose: Overload the / operator 
//Parameters: The ComplexNumber on the right side of the operator
//Returns: A new ComplexNumber object containing the quotient
ComplexNumber operator/(const ComplexNumber&) const;

//assignment
//Purpose: Overload the = operator
//Parameters: The two ComplexNumbers we want to assign
//Returns: 
ComplexNumber operator=(const ComplexNumber&);

//comparison
//Purpose: Overload the == operator 
//Parameters: The two ComplexNumbers we want to compare
//Returns: 
bool operator==(const ComplexNumber&) const;

private:
double complexNumberValue;
double realNumberValue;
};

//Independant Functions

//streamInsertionOverload
//Purpose: Overload the stream insertion operator
//Parameters: The stream object to read from, and object to read to
//Returns:The stream
ostream& operator<<(const ostream&, const ComplexNumber&);

这是我的错误

错误1错误LNK2019：函数_main中引用的未解析的外部符号“public：bool __thiscall ComplexNumber :: operator ==（class ComplexNumber const＆）const”（?? 8ComplexNumber @@ QBE_NABV0 @@ Z）

错误2错误LNK2019：未解析的外部符号“class std :: basic_ostream>＆__ cdecl operator <<（class std :: basic_ostream> const＆，class ComplexNumber const＆）”（?? 6 @ YAAAV？$ basic_ostream @ DU？$ char_traits @ D @ std @@@ std @@ ABV01 @ ABVComplexNumber @@@ Z）在函数_main中引用

错误3错误LNK2019：未解析的外部符号“public：double __thiscall ComplexNumber :: getValue（void）const”（？getValue @ ComplexNumber @@ QBENXZ）在函数“class std :: basic_ostream>＆__cdecl operator <<中引用（类std： ：basic_ostream>＆，类ComplexNumber const＆）“（?? 6 @ YAAAV？$ basic_ostream @ DU？$ char_traits @ D @ std @@@ std @@ AAV01 @ ABVComplexNumber @@@ Z）

错误4错误LNK1120：3个未解析的外部