docs/csharp/language-reference/statements/snippets/selection-statements/SwitchStatement.cs - main - aprogrammer/dotnet-docs

docs/csharp/language-reference/statements/snippets/selection-statements/SwitchStatement.cs
93 строки3 KB
Tom Dykstra
Update snippets for NRT (#28615)
11 мар 2022, 00:02
11 мар 2022, 00:02aff1571
namespace SelectionStatements;

public static class SwitchStatement
{
    public static void Examples()
    {
        Example();
        MultipleCases();
        WithCaseGuard();
    }

    private static void Example()
    {
        // <Example>
        DisplayMeasurement(-4);  // Output: Measured value is -4; too low.
        DisplayMeasurement(5);  // Output: Measured value is 5.
        DisplayMeasurement(30);  // Output: Measured value is 30; too high.
        DisplayMeasurement(double.NaN);  // Output: Failed measurement.

        void DisplayMeasurement(double measurement)
        {
            switch (measurement)
            {
                case < 0.0:
                    Console.WriteLine($"Measured value is {measurement}; too low.");
                    break;

                case > 15.0:
                    Console.WriteLine($"Measured value is {measurement}; too high.");
                    break;

                case double.NaN:
                    Console.WriteLine("Failed measurement.");
                    break;

                default:
                    Console.WriteLine($"Measured value is {measurement}.");
                    break;
            }
        }
        // </Example>
    }

    private static void MultipleCases()
    {
        // <MultipleCases>
        DisplayMeasurement(-4);  // Output: Measured value is -4; out of an acceptable range.
        DisplayMeasurement(50);  // Output: Measured value is 50.
        DisplayMeasurement(132);  // Output: Measured value is 132; out of an acceptable range.

        void DisplayMeasurement(int measurement)
        {
            switch (measurement)
            {
                case < 0:
                case > 100:
                    Console.WriteLine($"Measured value is {measurement}; out of an acceptable range.");
                    break;
                
                default:
                    Console.WriteLine($"Measured value is {measurement}.");
                    break;
            }
        }
        // </MultipleCases>
    }

    private static void WithCaseGuard()
    {
        // <WithCaseGuard>
        DisplayMeasurements(3, 4);  // Output: First measurement is 3, second measurement is 4.
        DisplayMeasurements(5, 5);  // Output: Both measurements are valid and equal to 5.

        void DisplayMeasurements(int a, int b)
        {
            switch ((a, b))
            {
                case (> 0, > 0) when a == b:
                    Console.WriteLine($"Both measurements are valid and equal to {a}.");
                    break;

                case (> 0, > 0):
                    Console.WriteLine($"First measurement is {a}, second measurement is {b}.");
                    break;

                default:
                    Console.WriteLine("One or both measurements are not valid.");
                    break;
            }
        }
        // </WithCaseGuard>
    }
}