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

docs/csharp/language-reference/statements/snippets/selection-statements/IfStatement.cs

79 строк2 KB

Tom Dykstra

Update snippets for NRT (#28615)

11 мар 2022, 00:02

11 мар 2022, 00:02aff1571

namespace SelectionStatements;

public static class IfStatement
{
    public static void Examples()
    {
        IfElse();
        OnlyIf();
        NestedIf();
    }

    private static void IfElse()
    {
        // <IfElse>
        DisplayWeatherReport(15.0);  // Output: Cold.
        DisplayWeatherReport(24.0);  // Output: Perfect!

        void DisplayWeatherReport(double tempInCelsius)
        {
            if (tempInCelsius < 20.0)
            {
                Console.WriteLine("Cold.");
            }
            else
            {
                Console.WriteLine("Perfect!");
            }
        }
        // </IfElse>
    }

    private static void OnlyIf()
    {
        // <OnlyIf>
        DisplayMeasurement(45);  // Output: The measurement value is 45
        DisplayMeasurement(-3);  // Output: Warning: not acceptable value! The measurement value is -3

        void DisplayMeasurement(double value)
        {
            if (value < 0 || value > 100)
            {
                Console.Write("Warning: not acceptable value! ");
            }

            Console.WriteLine($"The measurement value is {value}");
        }
        // </OnlyIf>
    }

    private static void NestedIf()
    {
        // <NestedIf>
        DisplayCharacter('f');  // Output: A lowercase letter: f
        DisplayCharacter('R');  // Output: An uppercase letter: R
        DisplayCharacter('8');  // Output: A digit: 8
        DisplayCharacter(',');  // Output: Not alphanumeric character: ,

        void DisplayCharacter(char ch)
        {
            if (char.IsUpper(ch))
            {
                Console.WriteLine($"An uppercase letter: {ch}");
            }
            else if (char.IsLower(ch))
            {
                Console.WriteLine($"A lowercase letter: {ch}");
            }
            else if (char.IsDigit(ch))
            {
                Console.WriteLine($"A digit: {ch}");
            }
            else
            {
                Console.WriteLine($"Not alphanumeric character: {ch}");
            }
        }
        // </NestedIf>
    }
}