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