C# out参数

C＃提供out关键字以将参数作为out-type传递。它类似于引用类型，只是它不需要变量在传递之前进行初始化。我们必须使用out关键字将参数作为out-type传递。当我们想要一个函数返回多个值时，这很有用。

C＃输出参数示例1

using System;
namespace OutParameter
{
    class Program
    {
        // User defined function
        public void Show(out int val) // Out parameter
        {
            int square = 5;
            val = square;
            val *= val; // Manipulating value
        }
        // Main function, execution entry point of the program
        static void Main(string[] args)
        {
            int val = 50;
            Program program = new Program(); // Creating Object
            Console.WriteLine("Value before passing out variable " + val);
            program.Show(out val); // Passing out argument
            Console.WriteLine("Value after recieving the out variable " + val);
        }
    }
}

输出：

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

下面的示例演示函数如何返回多个值。

C＃输出参数示例2

using System;
namespace OutParameter
{
    class Program
    {
        // User defined function
        public void Show(out int a, out int b) // Out parameter
        {
            int square = 5;
            a = square;
            b = square;
            // Manipulating value
            a *= a; 
            b *= b;
        }
        // Main function, execution entry point of the program
        static void Main(string[] args)
        {
            int val1 = 50, val2 = 100;
            Program program = new Program(); // Creating Object
            Console.WriteLine("Value before passing \n val1 = " + val1+" \n val2 = "+val2);
            program.Show(out val1, out val2); // Passing out argument
            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