Question

C# Simple Text File Merging Application - The idea is to merge two text files located in the same folder to create a new txt file (also in the same folder). I have the idea, and I can merge the two txt files together, however I would like to have an empty line between the two files. How would I implement this in the code below?

if (File.Exists(fileNameWithPath1))
{

try
{
string[] file1 = File.ReadAllLines(fileNameWithPath1);
string[] file2 = File.ReadAllLines(fileNameWithPath2);

//dump file, I clear and save it after each run
using (StreamWriter FileWriter = File.CreateText(@"//Destination"))
{
for(int i = 0; i < file1.Length || i < file2.Length; i++)
{
if (i < file1.Length)
FileWriter.WriteLine(file1[i]);
if (i < file1.Length)
FileWriter.WriteLine(file2[i]);

}
Console.WriteLine("File Added Succesfully");

Answer 1

using System;
using System.Collections.Generic;
using System.Data;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.IO;
using System.Data.OleDb;

namespace MergeProject
{

public class Program
{
public static void Main(string[] args)
{

string folderPath = @"C:\MergeFolder";
string firstFile = "firstFile.txt";
string secondFile = "secondFile.txt";
string targetFile = "targetFile.txt";
mergeTwoFiles(folderPath, firstFile, secondFile, targetFile);
Console.ReadLine();
}
      
       public static void mergeTwoFiles(string folderPath, string firstFile, string secondFile, string targetFile)
{

try
{
string firstFileFullPath = Path.Combine(folderPath, firstFile);
string secondFileFullPath = Path.Combine(folderPath, secondFile);
string targetFileFullPath = Path.Combine(folderPath, targetFile);

//check If directory exist
if (!Directory.Exists(folderPath))
{
Console.WriteLine("The directory {0} does not exist", folderPath);
return;
}

//remove existing Target File if it exist
if (File.Exists(targetFileFullPath))
{
File.Delete(targetFileFullPath);

}
//create new TargetFile
using (File.Create(targetFileFullPath))
{

}

string[] firstFileContent = new string[] { };

//check if file Exist and load to array [first File Contents]
if (File.Exists(firstFileFullPath))
{
firstFileContent = File.ReadAllLines(firstFileFullPath);
}
//check if file Exist and load to array
using (StreamWriter FileWriter = new StreamWriter(targetFileFullPath))
{
for (int i = 0; i < firstFileContent.Length; i++)
{
FileWriter.WriteLine(firstFileContent[i]);
}
}

//check if file Exist and load to array [second file Content]
string[] secondFileContent = new string[] { };
if (File.Exists(Path.Combine(folderPath, secondFile)))
{
secondFileContent = File.ReadAllLines(secondFileFullPath);
}

//check if file Exist and load to array
using (StreamWriter FileWriter = new StreamWriter(targetFileFullPath, true))
{

//check if new line is needed
if (firstFileContent.Length > 0 && secondFileContent.Length > 0)
{
FileWriter.WriteLine(); // Adding new line after a file Read
}

//add content of second file
for (int i = 0; i < secondFileContent.Length; i++)
{
FileWriter.WriteLine(secondFileContent[i]);
}
}
Console.WriteLine("File Added Succesfully");
}
catch (Exception)
{
Console.WriteLine("File Merge Operation Eror");
throw;
}

  
}
      
   }
}  

----input File--

firstFile.txt
12345678
6374739
938493
34
37488

secondFile.txt
ABC
DEF      

--------output File------------
targetFile.txt  
12345678
6374739
938493
34
37488

ABC
DEF