Select string from certain character until certain character in c#

Question

Okay so my code looks kinda like this

        // Returns the note of a favorite pown if it exists
        string GetFavoriteNote(int id)
        {
            string notelist = Properties.Settings.Default.FavoriteNotesList;

            // If there's a note, return it
            if (notelist.Contains("'" + id + ":"))
            {
                // What to do here?
            }
            // If there's no note, return an empty string
            else
            {
                return String.Empty;
            }
        }

Now it's basically a system where for each id the user can set a note, and it will be saved in this format: 'id:note','id:note' ,

Now what I want to do is select that note somehow and return it, so I'd have to like select from "'" + id + ":" until the '

If anyone knows how to do this, please help me out. Thanks

Answer 1

Using a Regex seems like the cleanest approach to me:

string regexFormat = "'{0}:(.*?)'";
Match match = Regex.Match(notelist, string.Format(regexFormat, id));
return match.Success ? match.Groups[1].Value : string.Empty;

Alternatively however, you could use string splitting:

var notes = notelist.Split(',');
var idString = "'" + id + ":";
var note = notes.FirstOrDefault(n => n.StartsWith(idString));
if (note == null) return string.Empty;
return note.Substring(idString.Length, note.Length - (idString.Length + 1));

Answer 2

try

int StartIndex = notelist.IndexOf("'" + id.ToString() + ":");
string result = string.Empty;
if ( StartIndex >= 0 )
{
     string tempstr = notelist.SubString ( StartIndex + ("'" + id.ToString() + ":").Length );
     result = tempstr.SubString ( 0, tempstr.IndexOf ( "'" ) );
}

return result;

Answer 3

As far I understood your code, following code will kinda give you a solution

            string IdWithNote = string.Empty;
            string noteList = Properties.Settings.Default.FavoriteNotesList;//your string type note list
            List<string> listNote = new List<string>();//newly created string type collection
            listNote=noteList.Split(',').ToList<string>();

            int index=listNote.IndexOf("'" + id + ":");
            if (index > -1)
                IdWithNote = listNote[index];
            return IdWithNote;

Answer 4

Old fashoned & clear (no regex) Also assumes you only want the text of the note, not the entire note structure.

string key = "'" + id + ":";
int noteStart = noteList.IndexOf(key);
if (noteStart >= 0)
{
    int textStart = noteStart + key.Length;
    int textEnd = noteList.IndexOf("'", textStart);
    return noteList.Substring(textStart, textEnd - textStart);
}
return "";

Answer 5

var myId=2;
var t="'1:note1','2:note2'";
var query = t.Split(',').Select(c => c.Replace("'", "").Split(':')).
                         Where(c => c[0] == myId.ToString()).
                         Select(p=>p[1]).First();

Answer 6

Here is a bit of code - the line you really wanted is: retVal = noteList.Substring(startIndex, endIndex - startIndex);

        int id = 8;
        string noteList = "'8:the note i want','81:the note i do not want'";
        string toFind = "'" + id.ToString() + ":";
        int startIndex = noteList.IndexOf(toFind) + toFind.Length;
        int endIndex = noteList.IndexOf("'", startIndex);
        if (noteList.Contains(toFind))
        {
            retVal = noteList.Substring(startIndex, endIndex - startIndex);
        }
        else
        {
            retVal = "nothing found";
        }

Answer 7

notelist.Substring(notelist.IndexOf("'" + id + ":"), (notelist.IndexOf("'") - notelist.IndexOf("'" + id + ":")));

this should do the trick, you can select the text by a substring into a new string. substring(startindex, lenght);