Question

How can I sort an IEnumerable<string> alphabetically. Is this possible?

Edit: How would I write an in-place solution?

Answer 1

The same way you’d sort any other enumerable:

var result = myEnumerable.OrderBy(s => s);

or

var result = from s in myEnumerable
             orderby s
             select s;

or (ignoring case)

var result = myEnumerable.OrderBy(s => s,
                                  StringComparer.CurrentCultureIgnoreCase);

Note that, as is usual with LINQ, this creates a new IEnumerable<T> which, when enumerated, returns the elements of the original IEnumerable<T> in sorted order. It does not sort the IEnumerable<T> in-place.

---

An IEnumerable<T> is read-only, that is, you can only retrieve the elements from it, but cannot modify it directly. If you want to sort a collection of strings in-place, you need to sort the original collection which implements IEnumerable<string>, or turn an IEnumerable<string> into a sortable collection first:

List<string> myList = myEnumerable.ToList();
myList.Sort();

---

Based on your comment:

_components = (from c in xml.Descendants("component")
               let value = (string)c
               orderby value
               select value
              )
              .Distinct()
              .ToList();

or

_components = xml.Descendants("component")
                 .Select(c => (string)c)
                 .Distinct()
                 .OrderBy(v => v)
                 .ToList();

or (if you want to later add more items to the list and keep it sorted)

_components = xml.Descendants("component")
                 .Select(c => (string)c)
                 .Distinct()
                 .ToList();

_components.Add("foo");
_components.Sort();