Prompts

Ask a yes/no question

// Simple yes/no prompt with default value
var proceed = Prompt.YesNo("Do you want to continue?", defaultValue: true);
// Displays: Do you want to continue? [Y/n]
// User can press Enter to use default (true)

// Without default value
var confirm = Prompt.YesNo("Are you sure?", defaultValue: null);
// Displays: Are you sure? [y/n]
// User must enter y or n

// Custom yes/no labels
var delete = Prompt.YesNo("Delete file?", "Yes", "No", defaultValue: false);
// Displays: Delete file? [y/N]

// Prompts are case-insensitive and loop until valid input
var result = Prompt.YesNo("Enable feature?", defaultValue: true);
if (result)
{
    Console.WriteLine("Feature enabled!");
}

Prompt.YesNo writes the question followed by the two answers in brackets, then reads a line from the console:

• The answers are compared without case: y, Y, yes with the Yes label, and so on.
• An empty line returns the default value. Without a default value (null), the question is asked again.
• Any other answer asks the question again, until the user gives a valid one.

With the overload that takes only a default value, the labels are y and n, and the default answer is shown in upper case: [Y/n] when the default is true, [y/N] when it is false, [y/n] when there is none. With custom labels, the labels are shown as you write them: write the default answer in upper case to show it.

Closed input

When the standard input is closed, for instance when it is redirected from an empty file or the application runs without a console, YesNo returns the default value. Without a default value it throws an EndOfStreamException rather than waiting forever: pass a default value when the application can run unattended.