C#函數如何?類似多個傳回值的功能

C#中函數是不具備返回多個值的功能，因此我們要實作類別似的功能，可從以下幾個方面考慮

• 在方法中傳入參數
• out/ref
• 返回數組
• 返回某個對象的執行個體

1.方法中傳入參數

using System;namespace MultiReturn{    class Arithmetic    {        class JiaJian        {            public double a;            public double b;            public double computing(string method)            {                switch (method)                {                    case "+":                        return a + b;                    case "-":                        return a - b;                    default :                       return 00000;;                }            }        }

    }

}

主函數

        static void Main(string[] args)        {            double c, d;            JiaJian MyArithmetic = new JiaJian();            MyArithmetic.a = 3;            MyArithmetic.b = 1;            c = MyArithmetic.computing("+");            d = MyArithmetic.computing("-");            Console.WriteLine("{0},{1}",c,d);            Console.ReadKey();        }

  

2,OUT/REF

 using System;
namespace MultiReturn
{
    class Arithmetic
    {
        class JiaJian
        {
            public
void computing(double a,double b,
out  double c,out
double d)
            {
                c = a + b;
                d = a - b;
            }
        }
        static
void Main(string[] args)
        {
            double c,d;
            JiaJian MyArithmetic = new JiaJian();
            MyArithmetic.computing(3,
1, out c, out d);
            Console.WriteLine("{0},{1}",c,d);
            Console.ReadKey();
        }
    }
}

 3、返回數組

傳回值數量較多的時候使用Array容易出現記憶體溢出的問題，因此考慮使用List<>;

而且使用List<object>還有可以返回任意類型資料的優點；

using System;using System.Collections.Generic;namespace MultiReturn{    class Arithmetic    {        class JiaJian        {            public double a, b;            public List<object>  computing()            {                List<object> result = new List<object>();                result.Add("四則運算");                result.Add(a + b);                result.Add(a - b);                return result;            }        }        static void Main(string[] args)        {            List<object> outcome;            JiaJian MyArithmetic = new JiaJian();            MyArithmetic.a = 3;            MyArithmetic.b = 1;            outcome = MyArithmetic.computing();            Console.WriteLine("{0}\n{1}\n{2}\n",outcome[0],outcome[1], outcome[2]);            Console.ReadKey();        }    }}

4,、返回某個對象的執行個體

 using System;
using System.Collections.Generic;
namespace MultiReturn
{
    class Arithmetic
    {
        class Example
        {
            public
double a, b;
            public
string c;
        }
        class JiaJian
        {
            public
double a, b;
            public Example computing()
            {
                Example example = new Example();
                example.a = this.a +
this.b;
                example.b = this.a -
this.b;
                example.c = "四則運算";
                return example;
            }
        }
        static
void Main(string[] args)
        {
            JiaJian MyArithmetic = new JiaJian();
            Example result = new Example();
            MyArithmetic.a = 3;
            MyArithmetic.b = 1;
            result = MyArithmetic.computing();
            Console.WriteLine("{0}\n{1}\n{2}\n", result.a, result.b, result.c);
            Console.ReadKey();
        }
    }
}