Can Console.Clear() Erase a Single Line, and If Not, How Can I Do It?

Can Console.Clear Be Used to Erase a Single Line in the Console?

While exploring the capabilities of Console.Clear(), a developer encountered the need to selectively erase specific lines in the console, leaving other content intact. This question delves into the nuances of erasing content on the console, both by reference and value.

Understanding Console Clearing

Console.Clear() typically clears the entire contents of the console screen. However, for certain scenarios, it may be desirable to erase only a single line. This is particularly relevant when working with a series of questions and answers where it's necessary to erase the question and display only the answer.

Limitations of Value Types

When passing values by value, the original variable is not affected by subsequent changes. This presents a challenge for selectively erasing lines containing values returned by value. As such, the main function does not have access to these values to erase and output them again.

Alternative: Controlling Cursor Position

To selectively erase a single line, the Console.SetCursorPosition function can be utilized. This function allows the programmer to move the cursor to any specified line number. By combining Console.SetCursorPosition with a custom function for clearing a specific line, it becomes possible to erase selected lines without affecting other screen content.

Custom Line Clearing Function

The following code snippet demonstrates a custom function named ClearCurrentConsoleLine() that addresses the need to erase a single line:

public static void ClearCurrentConsoleLine()
{
    int currentLineCursor = Console.CursorTop;
    Console.SetCursorPosition(0, Console.CursorTop - 1);
    Console.Write(new string(' ', Console.WindowWidth)); 
    Console.SetCursorPosition(0, currentLineCursor);
}

Usage Example

The usage of the ClearCurrentConsoleLine() function is exemplified in the following code:

Console.WriteLine("Test");
Console.SetCursorPosition(0, Console.CursorTop - 1);
ClearCurrentConsoleLine();

In this example, the string "Test" is written to the console, and then the cursor is moved up one line. The ClearCurrentConsoleLine() function is invoked to erase the line containing the test output, leaving the console with an empty line.

Additional Resources:

• [Console.SetCursorPosition Method](https://docs.microsoft.com/en-us/dotnet/api/system.console.setcursorposition?view=netcore-3.1)

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