Delete a carriage return in a txt file

Question

I create a program that uses a txt file that looks like this:

01/11 09:56,yeo,no,110222100,no
01/11 09:55,Test,Test2,110222100,Test2
01/11 09:52,Jack,Jean,112222100,Jean
31/10 23:17,Rayane,Jean,111220000,Rayane

I would then like a line in this file to delete it, so I use this code:

for (int i = 0; i < lignes.Count; i++)
{
    string ligne = lignes[i];
    List<string> element = ligne.Split(',').ToList();

    if (element.Contains(selectionDate[1])) //Ici on à les éléments de la ligne séléctionner
    {
        string ligneAr = null;
        lignes[i] = ligneAr;
        File.WriteAllLines(path, lignes);
    }
}

But, when I use this code, this is what happens in the txt file:

01/11 09:56,yeo,no,110222100,no
01/11 09:55,Test,Test2,110222100,Test2
01/11 09:52,Jack,Jean,112222100,Jean
31/10 23:17,Rayane,Jean,111220000,Rayane
// Empty line
31/10 22:30,Rayane,André,122120101,Rayane

There's a hole in the text instead. How can I delete this hole? The code that allows you to create it is in the if()

Thank you.

Answer 1

Hole which you mentioned in your question is added due to assigning null to lignes[i] i.e lignes[i] = ligneAr;. File.WriteAllLines() inside for loop, is also wrong place to update your file.

No need to split your string lignes[i], you can just use .Where() clause with required condition to get filtered result and write it to the file.

Something like,

var result = lignes.Where(ligne => !ligne.Contains(selectionDate[1]));
File.WriteAllLines(path, result);