Console.KeyAvailable() Property in C#

Console.KeyAvailable Property is used to get a value which shows whether a key press is available in the input stream. This property does not block input until a key press is available.

Syntax: public static bool KeyAvailable { get; } 
Property Value: It will return true if a key press is available otherwise, it returns false. 

Exceptions:

• InvalidOperationException: If the standard input is redirected to a file instead of the keyboard.
• IOException: If an I/O error occurred.

Example:

C#

// C# Program to demonstrate
// KeyAvailable property
using System;
using System.Threading;

namespace GFG {

class GFG {

    public static void Main()
    {
        // declare a new ConsoleKeyInfo object
        ConsoleKeyInfo c = new ConsoleKeyInfo();

        // outer loop to work until 'z' is pressed
        do {
            Console.WriteLine("\nPress a key to display; "+
                              "press the 'z' key to quit.");

            // inner loop to check whether a key
            // is pressed using KeyAvailable
            while (Console.KeyAvailable == false)

                // Loop until input is entered.
                Thread.Sleep(50);
            c = Console.ReadKey(true);
            Console.WriteLine("You pressed the '{0}' key.", c.Key);

        } while (c.Key != ConsoleKey.Z);
    }
}
}

Output:

Reference:

• https://docs.microsoft.com/en-us/dotnet/api/system.console.keyavailable?view=netframework-4.7.2