ObservableCollection find item match on reference equality

Its late so this may be a dumb question... If Fish is a class (with no Equal/operator== overrides/overloads) and I want to get a specific fish matched on reference equality from a List or ObservableCollection of Fish(es) currently I do:

Fish found_fish1 = my_list.Find(f => f==search_fish);
Fish found_fish2 = my_observable_collection.FirstOrDefault(f => f==search_fish);

Is that the best way to do this? I was expecting an XXXX method that takes a Fish (similar to Remove) eg

Fish found_fish = my_observable_collection.XXXX(search_fish);

but just can't seem to find it.


Since found_fish is either search_fish or null, you can use ICollection<T>.Contains:

Fish found_fish1 =
    my_list.Contains(search_fish) ? search_fish : null;
Fish found_fish2 =
    my_observable_collection.Contains(search_fish) ? search_fish : null;

Yes, that is the correct way.

Find takes a Preciate<Fish>, and FirstOrDefault takes a Func<Fish, bool>, so your signature will work for both; both signatures expect a single Fish, and a return value of boolean.

But since you're really just testing to see if a given fish is in your collection, why not just use Any()

bool searchFishExists = my_observable_collection.Any(f => f == search_fish);

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