Console.WriteLine() / Console.Write()

// Outputs text and moves to the next line.
Console.WriteLine(value)
Console.WriteLine(string format, params object[] args)

// Outputs text without moving to the next line.
Console.Write(value)
Console.Write(string format, params object[] args)

Method	Description
Console.WriteLine(value)	Converts a value to a string, outputs it, and appends a newline. Calling it with no arguments outputs a blank line.
Console.Write(value)	Outputs a value without a newline. Use this when you want to output multiple values on the same line.
Console.WriteLine(format, arg0, arg1)	Outputs values embedded in a format string using placeholders ({0}, {1}).
Console.ForegroundColor	Sets the text color of the output (specify a ConsoleColor enum value).
Console.ResetColor()	Resets the text color and background color to their defaults.

Program.cs

using System;

// Basic output
Console.WriteLine("Hello, World!");
Console.WriteLine(42);
Console.WriteLine(3.14);
Console.WriteLine(true);

// Write() does not add a newline
Console.Write("Name: ");
Console.Write("Gojo Satoru");
Console.WriteLine(" san"); // Newline is added here

// Embed values using a format string
string name = "Itadori Yuji";
int age = 15;
Console.WriteLine("{0} is {1} years old.", name, age);

// String interpolation ($"...") offers a more intuitive syntax
Console.WriteLine($"{name} is {age} years old.");

Run the following command:

dotnet run
Hello, World!
42
3.14
True
Name: Gojo Satoru san
Itadori Yuji is 15 years old.
Itadori Yuji is 15 years old.

You can format numbers, dates, percentages, and more.

FormatSample.cs

using System;

double price = 1234.5;
Console.WriteLine($"Price: {price:N0} yen"); // Integer with thousands separator
Console.WriteLine($"Rate: {0.756:P1}"); // Percentage with 1 decimal place
Console.WriteLine($"Date: {DateTime.Now:yyyy/MM/dd}");
Console.WriteLine($"Fixed decimal: {price:F2}"); // 2 decimal places
Console.WriteLine($"Hex: {255:X}"); // Hexadecimal

Run the following command:

dotnet run
Price: 1,234 yen
Rate: 75.6%
Date: 2026/03/31
Fixed decimal: 1234.50
Hex: FF

Use Console.ForegroundColor to change the text color. After use, call Console.ResetColor() to restore the default color.

ColorOutput.cs

using System;

Console.ForegroundColor = ConsoleColor.Red;
Console.WriteLine("Error message (red)");
Console.ResetColor();

Console.ForegroundColor = ConsoleColor.Green;
Console.WriteLine("Success message (green)");
Console.ResetColor();

Console.ForegroundColor = ConsoleColor.Yellow;
Console.WriteLine("Warning message (yellow)");
Console.ResetColor();

Console.WriteLine("Back to the default color.");

Run the following command:

dotnet run
Error message (red)
Success message (green)
Warning message (yellow)
Back to the default color.

Common Mistake: Forgetting a Newline After Write()

If you do not add a newline after Console.Write(), the next output will appear on the same line.

using System;

// NG: Without a newline after Write(), the next output is appended on the same line
Console.Write("Processing...");
Console.WriteLine("Done"); // Outputs "Processing...Done" on one line

The following example demonstrates this:

dotnet run
Processing...Done

The following example demonstrates this:

using System;

// OK: Add a newline after Write() when needed
Console.Write("Processing...");
Console.WriteLine(); // Output newline only
Console.WriteLine("Done");

The following example demonstrates this:

dotnet run
Processing...
Done

Console.WriteLine() is the most commonly used output method in C#. String interpolation ($"...") lets you embed variables directly into a string, resulting in more readable code than format strings ({0}).

Useful numeric format specifiers include :N0 (integer with thousands separator), :F2 (2 decimal places), and :P1 (percentage with 1 decimal place). For a full list of format specifiers, refer to the .NET format string documentation.

To read input from the console, see Console.ReadLine() / Console.ReadKey().