Yes, they will be: GroupBy (MSDN). The IGrouping<TKey, TElement> objects are yielded in an order based on the order of the elements in source that produced the first key of each IGrouping<TKey, TElement>. Elements in a grouping are yielded in the order they appear in source.
It won’t be much more efficient, however it would be a bit cleaner to do something like: var strings = new string[] { “1”, “02”, “003”, “0004”, “00005” }; string longest = strings.OrderByDescending( s => s.Length ).First(); Output: 00005
Have a look at the Except method, which you use like this: var resultingList = listOfOriginalItems.Except(listOfItemsToLeaveOut, equalityComparer) You’ll want to use the overload I’ve linked to, which lets you specify a custom IEqualityComparer. That way you can specify how items match based on your composite key. (If you’ve already overridden Equals, though, you shouldn’t need … Read more
int[] intarray = { 1, 2, 3, 4, 5 }; string[] result = intarray.Select(x=>x.ToString()).ToArray();
List<B> listB = listA.Select(a => new B() { Count = a.TotalCount, Title = a.Title }).ToList(); Does the same as eduncan’s solution with different syntax. Take your pick..
That is definitely not the case. LINQ-to-Objects is a set of extension methods on IEnumerable<T> that allow you to perform in-memory query operations on arbitrary sequences of objects. The methods accept simple delegates when necessary. LINQ-to-Entities is a LINQ provider that has a set of extension methods on IQueryable<T>. The methods build up an expression … Read more
It’s not broken. SkipWhile will only skip items in the beginning of the IEnumerable<T>. Once that condition isn’t met it will happily take the rest of the elements. Other elements that later match it down the road won’t be skipped. int[] sequence = { 3, 3, 1, 1, 2, 3 }; var result = sequence.SkipWhile(i … Read more
DefaultIfEmpty method should help: int new_id = C_Movement.list.Select(x => x.id).DefaultIfEmpty(-1).Max()+1;
var products = shopProducts.Where(p => listOfProducts.Any(l => p.Name == l.Name)) .ToList(); For LINQ-to-Objects, if listOfProducts contains many items then you might get better performance if you create a HashSet<T> containing all the required names and then use that in your query. HashSet<T> has O(1) lookup performance compared to O(n) for an arbitrary IEnumerable<T>. var names … Read more
You could try something like: var differences = list2.Where(l2 => !list1.Any(l1 => l1.Name == l2.Name && l1.Size == l2.Size)); Or if you prefer: var differences = list2.Where(l2 => list1.All(l1 => l1.Name != l2.Name || l1.Size != l2.Size));