Is it possible to sort a HashTable?

Question

I have a property that returns a HashTable. I would like to sort it without refactoring my property. Please note: I do not want to return another type.

Answer 1

Another option is to construct the hash table as you're already doing, and then simply construct a sorted set from the keys. You can iterate through that sorted key set, fetching the corresponding value from the hash table as needed.

Answer 2

You can also use DataView to sort the Hashtable. Here is an article that I wrote 5 years ago: http://www.codeproject.com/Articles/37039/Sorting-Hashtable

Answer 3

Not exactly a C# answer but I am sure you can make something of it.

In Perl it is common to "sort" a hash table for use in output to the display.

For example:

print "Items: ";
foreach (sort keys %items) {
    print $_, '=', $items{$_}, ' ';
}

The trick here is that Perl doesn't sort the hash, it is sorting a copied list of hash keys. It should be easy enough in C# to extract the hash keys into a list and then sort that list.

Answer 4

Of course hash tables can be sorted, but you need to first define what it means to sort a hash table. (Therein lies the issue)

Once you have done that, however, you've invariably removed all the advantages that a hashtable can give you, and you might as well use a sorted array (with binary searching), or use a red-black tree instead.

Answer 5

Hashtables work by mapping keys to values. Implicit in this mapping is the concept that the keys aren't sorted or stored in any particular order.

However, you could take a look at SortedDictionary<K,V>.

Answer 6

There is no point in sorting a hash table because you already have almost constant lookup time. Or at worst O(B) where B is the bucket size.