C Write to File
To write text to file in C#, you can use System.IO.File.WriteAllLines() function or System.IO.File.WriteAllText() function.
Or you can use WriteLine in recursive loop to write lines to a file. It gives more control on each line to be written.
Example 1 Write to Text File SystemIOFileWriteAllLines
System.IO.File.WriteAllLines() writes strings in an array, to a text file.
Program.cs
using System; namespace CSharpExamples { class Program { static void Main(string[] args) { string[] lines = { "Hello World.", "Welcome to C# Tutorial.", "TutorialKart." }; try{ System.IO.File.WriteAllLines(@"D:\lines.txt", lines); Console.WriteLine("Lines written to file successfully."); } catch(Exception err) { Console.WriteLine(err.Message); } } } }
Output
PS D:\workspace\csharp\HelloWorld> dotnet run Lines written to file successfully.
D:\lines.txt
Hello World. Welcome to C# Tutorial. TutorialKart.
Example 2 Write to Text File SystemIOFileWriteAllText
System.IO.File.WriteAllText() writes string to a text file specified by the argument passed to the function.
Program.cs
using System; namespace CSharpExamples { class Program { static void Main(string[] args) { string str = "Hello World. Welcome to C# Tutorial. TutorialKart."; try{ System.IO.File.WriteAllText(@"D:\sample.txt", str); Console.WriteLine("String written to file successfully."); } catch(Exception err) { Console.WriteLine(err.Message); } } } }
Output
PS D:\workspace\csharp\HelloWorld> dotnet run String written to file successfully.
D:\sample.txt
Hello World. Welcome to C# Tutorial. TutorialKart.
Example 3 Write to Text File WriteLine in Loop
In the following example, we get StreamWriter for a file and then write each line in the string array to the file.
Program.cs
using System; namespace CSharpExamples { class Program { static void Main(string[] args) { string[] lines = { "Hello World.", "Welcome to C# Tutorial.", "TutorialKart." }; try{ using (System.IO.StreamWriter file = new System.IO.StreamWriter(@"D:\lines.txt")) { foreach (string line in lines) { file.WriteLine(line); } } Console.WriteLine("Lines written to file successfully."); } catch(Exception err) { Console.WriteLine(err.Message); } } } }
Output
PS D:\workspace\csharp\HelloWorld> dotnet run Lines written to file successfully.
D:\lines.txt
Hello World. Welcome to C# Tutorial. TutorialKart.
Conclusion
In this C# Tutorial, we learned to write string to a text file, or lines stored in a string array to a text file.