How would I distinct my list of key/value pairs

Question

If I have a list List<KeyValuePair<string,string>>ex.

["abc","123"]
["asc","123"]
["asdgf","123"]
["abc","123"]

how can I distinc this list?

Dictionary is not a good answer: Does not distinct by value or by both AND gives you duplicate key exceptions before distinctin' it ;-) — D.R., Jul 30 '13 at 19:41

score 26 · Accepted Answer · answered Jul 30 '13 at 19:41

26

Distinct by both Key and Value:

var results = source.Distinct().ToList();

Distinct by Key or Value (just change the property on GroupBy call:

var results = source.GroupBy(x => x.Key).Select(g => g.First()).ToList();

answered Jul 30 '13 at 19:41

MarcinJuraszek

score -1 · Answer 2 · answered Jul 30 '13 at 19:39

-1

You should use a Set (of pair objects) if you wish to have distinct pairs or a Map/Dictionary if you wish to have distinct keys.

answered Jul 30 '13 at 19:39

Robadob

Does .NET have a proper Set collection? – D.R. Jul 30 '13 at 19:42
2

`ISet` is the interface, and `HashSet` is an implementation. Works as expected. – Jacob Jul 30 '13 at 19:42
The other usual `ISet<>` being `SortedSet<>`. Edit: Although the `SortedSet>` is only useful if given an `IComparer<>` when constructed. – Jeppe Stig Nielsen Jul 30 '13 at 19:51
My answer was answering the correct collection type that suits his need (no repeated items), the actual implementation of this collection type would depend on how he's going to use it which we don't know! – Robadob Jul 30 '13 at 19:55

2 Answers2