无涯教程-C# - Out参数

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C#提供out关键字将参数作为输出类型传递。它类似于引用类型,不同之处在于它在传递之前不需要初始化变量。无涯教程必须使用out关键字将参数作为输出类型传递。当无涯教程希望一个函数返回多个值时,它很有用。

C#输出参数示例1

using System;
namespace OutParameter
{
    class Program
    {
        // 用户定义的函数
        public void Show(out int val) // 输出参数
        {
            int square = 5;
            val = square;
            val *= val; // Manipulating value
        }
        
        static void Main(string[] args)
        {
            int val = 50;
            Program program = new Program(); // 创建对象
            Console.WriteLine("Value before passing out variable " + val);
            program.Show(out val); // 将输出参数传入函数
            Console.WriteLine("Value after recieving the out variable " + val);
        }
    }
}

输出:

Value before passing out variable 50
Value after receiving the out variable 25

下面的示例演示了函数如何返回多个值。

C#输出参数示例2

using System;
namespace OutParameter
{
    class Program
    {
        // 用户定义的函数
        public void Show(out int a, out int b) // 输出函数
        {
            int square = 5;
            a = square;
            b = square;
            // Manipulating value
            a *= a; 
            b *= b;
        }
        
        static void Main(string[] args)
        {
            int val1 = 50, val2 = 100;
            Program program = new Program(); //创建对象
            Console.WriteLine("Value before passing \n val1 = " + val1+" \n val2 = "+val2);
            program.Show(out val1, out val2); // 传递输出函数
            Console.WriteLine("Value after passing \n val1 = " + val1 + " \n val2 = " + val2);
        }
    }
}

输出:

Value before passing
 val1 = 50
 val2 = 100
Value after passing
 val1 = 25
 val2 = 25

参考链接

www.learnfk.com/csharp/c-sh…