Adding IEnumerable<T> items to IEnumerable<T> [duplicate]

Question

I have the following:

 foreach (var item in selected)
 {
    var categories = _repo.GetAllDCategories(item);
    var result = from cat in categories
                 select
                     new
                     {
                        label = cat.Name,
                        value = cat.Id
                     };
}

The method GetAllDCategories returns a IEnumerable<T>

How to add result to new IEnumerable object that will contain all the items from result for all the selected items in the loop?

Answer 1

Could you not use Concat?

Something like

        IEnumerable<string> s1 = new List<string>
                                    {
                                        "tada"
                                    };
        IEnumerable<string> s2 = new List<string>
                                    {
                                        "Foo"
                                    };
        s1 = s1.Concat(s2);

Answer 2

var result = selected.Select(item=>_repo.GetAllDCategories(item))
                     .SelectMany(x=>x,(x,cat)=> select new {
                                                   label = cat.Name, 
                                                   value = cat.Id
                                                });