You have a few issues here: first, strings are immutable, so when you call .Replace you return a new string. Calling n.Replace doesn’t modify n. assigning to n in your anonymous function won’t affect the value that’s in your list. regardless of the above, you can’t change the content of your collection while enumerating it, … Read more
You could do: bool onlyOne = source.Where(/*condition*/).Take(2).Count() == 1 Which will prevent count from enumerating a large sequence unnecessarily in the event of multiple matches.
Use this: items.Select(i => i.Value).Distinct().Count()
In order to use your multidimensional array with LINQ, you simply need to convert it to IEnumerable<T>. It’s simple enough, here are two example options for querying int[,] array = { { 1, 2 }, { 3, 4 } }; var query = from int item in array where item % 2 == 0 select … Read more
Edit: If you’re using EntityFramework >= 6.0, use DbFunctions.AddDays. For older versions of Entity Framework, use EntityFunctions.AddDays: var requestIgnored = context.Request .Where(c => c.IdRequest == result.IdRequest && c.IdRequestTypes == 1 && c.Accepted == false && DateTime.Now <= DbFunctions.AddDays(c.DateResponse, 30)) .SingleOrDefault();
Try the following var dictionary = sampleList .GroupBy(x => x.ResultString, x => x.ID) .ToDictionary(x => x.Key, x => x.ToList()); The GroupBy clause will group every Sample instance in the list by its ResultString member, but it will keep only the Id part of each sample. This means every element will be an IGrouping<string, int>. The … Read more
That’s what sets (e.g., HashSet<T>) are for. Sets have no defined order, and SetEquals verifies whether the set and another collection contain the same elements. var set = new HashSet<int>(list1); var equals = set.SetEquals(list2);
songs.UserSongs.GroupBy(x => x.User).Select(g => new SongsForUser() { User = g.Key, Songs = g.Select(s => s.SongId).ToList() });
OK, consider the following test: public class CleanString { //by MSDN http://msdn.microsoft.com/en-us/library/844skk0h(v=vs.71).aspx public static string UseRegex(string strIn) { // Replace invalid characters with empty strings. return Regex.Replace(strIn, @”[^\w\.@-]”, “”); } // by Paolo Tedesco public static String UseStringBuilder(string strIn) { const string removeChars = ” ?&^$#@!()+-,:;<>’\’-_*”; // specify capacity of StringBuilder to avoid resizing StringBuilder … Read more
The reason it is complaining is because it doesn’t know how to translate your Select() into a SQL expression. If you need to do a data transformation to a POCO that is not an entity, you should first get the relevant data from EF and then transform it to the POCO. In your case it … Read more