Your status-codes are also a collection, so use Contains: var allowedStatus = new[]{ “A”, “B”, “C” }; var filteredOrders = orders.Order.Where(o => allowedStatus.Contains(o.StatusCode)); or in query syntax: var filteredOrders = from order in orders.Order where allowedStatus.Contains(order.StatusCode) select order;
Using closures and anonymous method: List<Item> myList = FetchDataFromDatabase(); decimal currentTotal = 0; var query = myList .OrderBy(i => i.Date) .Select(i => { currentTotal += i.Amount; return new { Date = i.Date, Amount = i.Amount, RunningTotal = currentTotal }; } ); foreach (var item in query) { //do with item }
This will loop through only once. Item biggest = items.Aggregate((i1,i2) => i1.ID > i2.ID ? i1 : i2); Thanks Nick – Here’s the proof class Program { static void Main(string[] args) { IEnumerable<Item> items1 = new List<Item>() { new Item(){ ClientID = 1, ID = 1}, new Item(){ ClientID = 2, ID = 2}, new … Read more
Take the type/ID checking out of the recursion, so just have a “give me all the controls, recursively” method, e.g. public static IEnumerable<Control> GetAllControls(this Control parent) { foreach (Control control in parent.Controls) { yield return control; foreach(Control descendant in control.GetAllControls()) { yield return descendant; } } } That’s somewhat inefficient (in terms of creating lots … Read more
This can be done as list.Sort( (emp1,emp2)=>emp1.FirstName.CompareTo(emp2.FirstName) ); The .NET framework is casting the lambda (emp1,emp2)=>int as a Comparer<Employee>. This has the advantage of being strongly typed. If you need the descending/reverse order invert the parameters. list.Sort( (emp1,emp2)=>emp2.FirstName.CompareTo(emp1.FirstName) );
var distinctItems = items.GroupBy(x => x.Id).Select(y => y.First());
Just stumbled into this oldie… To do this without the dynamic LINQ library, you just need the code as below. This covers most common scenarios including nested properties. To get it working with IEnumerable<T> you could add some wrapper methods that go via AsQueryable – but the code below is the core Expression logic needed. … Read more