无涯教程-C# - Output parameters函数

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RETURN语句只能用于从函数返回一个值。但是,使用输出参数,您可以从一个函数返回两个值。输出参数类似于引用参数,不同之处在于它们将数据传输出方法,而不是将数据传输到方法中。

以下示例说明了此−

using System;

namespace CalculatorApplication {
   class NumberManipulator {
      public void getValue(out int x ) {
         int temp = 5;
         x = temp;
      }
      static void Main(string[] args) {
         NumberManipulator n = new NumberManipulator();
         
         /* local variable definition */
         int a = 100;
         
         Console.WriteLine("Before method call, value of a : {0}", a);
         
         /* calling a function to get the value */
         n.getValue(out a);

         Console.WriteLine("After method call, value of a : {0}", a);
         Console.ReadLine();
      }
   }
}

编译并执行上述代码时,将生成以下结果−

Before method call, value of a : 100
After method call, value of a : 5

为输出参数提供的变量不需要赋值。当您需要通过参数从方法返回值而不为参数分配初始值时,输出参数特别有用。查看以下示例,以了解此−

using System;

namespace CalculatorApplication {
   class NumberManipulator {
      public void getValues(out int x, out int y ) {
          Console.WriteLine("Enter the first value: ");
          x = Convert.ToInt32(Console.ReadLine());
          
          Console.WriteLine("Enter the second value: ");
          y = Convert.ToInt32(Console.ReadLine());
      }
      static void Main(string[] args) {
         NumberManipulator n = new NumberManipulator();
         
         /* local variable definition */
         int a , b;
         
         /* calling a function to get the values */
         n.getValues(out a, out b);
         
         Console.WriteLine("After method call, value of a : {0}", a);
         Console.WriteLine("After method call, value of b : {0}", b);
         Console.ReadLine();
      }
   }
}

编译并执行上述代码时,将生成以下结果−

Enter the first value:
7
Enter the second value:
8
After method call, value of a : 7
After method call, value of b : 8

参考链接

www.learnfk.com/csharp/csha…