How do you write structured data (like CSV) to a file in C#?

Question

ICSM Computer · Answer

In C#, you can write structured data like CSV using simple 
StreamWriter or File.WriteAllText/File.AppendAllText. CSV (Comma-Separated Values) format is just plain text with values separated by commas, and optionally enclosed in quotes if they contain commas or special characters.
Basic CSV Writing Example with StreamWriter
using System;
using System.IO;
class Program
{
    static void Main()
    {
        string csvPath = @"C:\output.csv";
        using (StreamWriter writer = new StreamWriter(csvPath))
        {
            // Write header
            writer.WriteLine("Id,Name,Email");
            // Write data rows
            writer.WriteLine("1,John Doe,john@example.com");
            writer.WriteLine("2,Jane Smith,jane@example.com");
            writer.WriteLine("3,\"O'Brien, Sam\",sam@example.com"); // Quotes needed for comma in name
        }
        Console.WriteLine("CSV written to: " + csvPath);
    }
}
Handling Special Characters
Enclose fields in double quotes if they contain commas, quotes, or newlines.
Escape quotes inside a field by doubling them:
"He said ""Hello""" → becomes He said "Hello"
Optional: Generate CSV from a List of Objects
class Person
{
    public int Id;
    public string Name;
    public string Email;
}
var people = new Listandlt;Personandgt;
{
    new Person { Id = 1, Name = "John Doe", Email = "john@example.com" },
    new Person { Id = 2, Name = "Jane Smith", Email = "jane@example.com" }
};
using (StreamWriter writer = new StreamWriter(@"C:\people.csv"))
{
    writer.WriteLine("Id,Name,Email");
    foreach (var person in people)
    {
        string name = person.Name.Contains(",") ? $"\"{person.Name}\"" : person.Name;
        writer.WriteLine($"{person.Id},{name},{person.Email}");
    }
}
Tip: Use a CSV library like CsvHelper for large or complex data sets.

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How do you write structured data (like CSV) to a file in C#?

ICSM Computer

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1 Answers

Basic CSV Writing Example with `StreamWriter`

Handling Special Characters

Optional: Generate CSV from a List of Objects

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