如何：使用运算符重载创建复数类（C# 编程指南）

本示例展示如何使用运算符重载创建定义复数加法的复数类 Complex。本程序使用 ToString 方法的重载显示数字的虚部和实部以及加法结果。

public struct Complex
{
    public int real;
    public int imaginary;

    // Constructor.
    public Complex(int real, int imaginary)  
    {
        this.real = real;
        this.imaginary = imaginary;
    }

    // Specify which operator to overload (+), 
    // the types that can be added (two Complex objects),
    // and the return type (Complex).
    public static Complex operator +(Complex c1, Complex c2)
    {
        return new Complex(c1.real + c2.real, c1.imaginary + c2.imaginary);
    }

    // Override the ToString() method to display a complex number 
    // in the traditional format:
    public override string ToString()
    {
        return (System.String.Format("{0} + {1}i", real, imaginary));
    }
}

class TestComplex
{
    static void Main()
    {
        Complex num1 = new Complex(2, 3);
        Complex num2 = new Complex(3, 4);

        // Add two Complex objects by using the overloaded + operator.
        Complex sum = num1 + num2;

        // Print the numbers and the sum by using the overridden 
        // ToString method.
        System.Console.WriteLine("First complex number:  {0}", num1);
        System.Console.WriteLine("Second complex number: {0}", num2);
        System.Console.WriteLine("The sum of the two numbers: {0}", sum);

        // Keep the console window open in debug mode.
        System.Console.WriteLine("Press any key to exit.");
        System.Console.ReadKey();
    }
}
/* Output:
    First complex number:  2 + 3i
    Second complex number: 3 + 4i
    The sum of the two numbers: 5 + 7i
*/

请参阅

C# 编程指南

C# 运算符

运算符（C# 参考）

Why are overloaded operators always static in C#?（在 C# 中，为什么重载的运算符始终是静态的？）