Programming Fundamentals/Files/C Sharp

files.cs

// This program creates a file, adds data to the file, displays the file,
// appends more data to the file, displays the file, and then deletes the file.
// It will not run if the file already exists.
//
// References:
//     https://www.mathsisfun.com/temperature-conversion.html
//     https://en.wikibooks.org/wiki/C_Sharp_Programming

using System;

public class Files
{
    public static void Main(String[] args)
    {
        string FILENAME = "~file.txt";
    
        if(System.IO.File.Exists(FILENAME))
        {
            System.Console.WriteLine("File already exists.\n");
        }
        else
        {
            CreateFile(FILENAME);
            ReadFile(FILENAME);
            AppendFile(FILENAME);
            ReadFile(FILENAME);
            DeleteFile(FILENAME);
        }
    }
    
    private static void CreateFile(string filename)
    {
        System.IO.StreamWriter file;
        float c;
        float f;
        
        file = System.IO.File.CreateText(filename);
        file.WriteLine("C\tF");
        for(c = 0; c <= 50; c++)
        {
            f = c * 9 / 5 + 32;
            file.WriteLine(c + "\t" + f);
        }
        file.Close();
    }
    
    private static void ReadFile(string filename)
    {
        System.IO.StreamReader file;
        string line;

        file = System.IO.File.OpenText(filename);
        while (true) 
        {
            line = file.ReadLine();
            if (line == null)
            {
                break;
            }
            Console.WriteLine(line);
        }
        file.Close();
        Console.WriteLine("");
    }
    
    private static void AppendFile(string filename)
    {
        System.IO.StreamWriter file;
        float c;
        float f;
        
        file = System.IO.File.AppendText(filename);
        for(c = 51; c <= 100; c++)
        {
            f = c * 9 / 5 + 32;
            file.WriteLine(c + "\t" + f);
        }
        file.Close();
    }
    
    private static void DeleteFile(string filename)
    {
        System.IO.File.Delete(filename);
    }
}
Try It

Copy and paste the code above into one of the following free online development environments or use your own C Sharp compiler / interpreter / IDE.
files.cs

Try It

See Also
