linq distinct list c# code example
Example 1: C# .NET Core linq Distinct
var distinctUsers = allUsers
.GroupBy(x => x.UserId)
.Select(x => x.First())
.ToList();
Example 2: how to use distinct in linq query in c#
var distValues = objList.Select(o=>o.typeId).Distinct().ToList();
Example 3: c# distinct array of objects by values
var uniquePersons = persons.GroupBy(p => p.Email)
.Select(grp => grp.First())
.ToArray();
Example 4: c# distinct comparer multiple properties
public static IEnumerable<TSource> DistinctBy<TSource, TKey>
(this IEnumerable<TSource> source, Func<TSource, TKey> keySelector)
{
HashSet<TKey> seenKeys = new HashSet<TKey>();
foreach (TSource element in source)
{
if (seenKeys.Add(keySelector(element)))
{
yield return element;
}
}
}
Example 5: linq distinct
var uniquePeople = from p in people
group p by new {p.ID}
into mygroup
select mygroup.FirstOrDefault();