编辑“︁C++ 运算符重载基础”︁（章节）

== 实际应用案例：复数类 ==
以下是一个更复杂的示例，展示如何为复数类重载多个运算符：

<syntaxhighlight lang="cpp">
#include <iostream>
#include <cmath>

class Complex {
private:
    double real, imag;

public:
    Complex(double r = 0, double i = 0) : real(r), imag(i) {}

    // 重载+运算符
    Complex operator+(const Complex& other) const {
        return Complex(real + other.real, imag + other.imag);
    }

    // 重载-运算符
    Complex operator-(const Complex& other) const {
        return Complex(real - other.real, imag - other.imag);
    }

    // 重载*运算符（复数乘法）
    Complex operator*(const Complex& other) const {
        return Complex(
            real * other.real - imag * other.imag,
            real * other.imag + imag * other.real
        );
    }

    // 重载<<运算符（用于输出）
    friend std::ostream& operator<<(std::ostream& os, const Complex& c) {
        os << "(" << c.real << " + " << c.imag << "i)";
        return os;
    }
};

int main() {
    Complex c1(1, 2);
    Complex c2(3, 4);

    std::cout << "c1 + c2 = " << (c1 + c2) << "\n";
    std::cout << "c1 - c2 = " << (c1 - c2) << "\n";
    std::cout << "c1 * c2 = " << (c1 * c2) << "\n";

    return 0;
}
</syntaxhighlight>

'''输出：'''
<pre>
c1 + c2 = (4 + 6i)
c1 - c2 = (-2 + -2i)
c1 * c2 = (-5 + 10i)
</pre>

'''解释：'''
1. 定义了一个<code>Complex</code>类表示复数。
2. 重载了<code>+</code>、<code>-</code>和<code>*</code>运算符，实现了复数的加法、减法和乘法。
3. 重载了<code><<</code>运算符，使复数可以直接输出到流中。