David.Chu.ca David.Chu.ca -4 years ago 182
C# Question

Find an item in List by LINQ?

Here I have a simple example to find an item in a list of strings. Normally I use for loop or anonymous delegate to do it like this:

int GetItemIndex(string search)
int found = -1;
if ( _list != null )
foreach (string item in _list) // _list is an instance of List<string>
if ( string.Equals(search, item) )
/* use anonymous delegate
string foundItem = _list.Find( delegate(string item) {
return string.Equals(search, item);
return found;

LINQ is new for me. I am curious if I can use LINQ to find item in list? How if possible?

Answer Source

There's a few ways (note this is not a complete list).

1) Single will return a single result, but will throw an exception if it finds none or more than one (which may or may not be what you want):

string search = "lookforme";
List<string> myList = new List<string>();
string result = myList.Single(s => s == search);

2) Where will return all items which match your criteria, so you may get an IEnumerable with one element:

IEnumerable<string> results = myList.Where(s => s == search);

3) First will return the first item which matches your criteria:

string result = myList.First(s => s == search);
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