How do I query list for any matches on item property?

Question

I have a List<Tuple<int, string>>. I want to get a bool indicating whether there is a match on any of the int values. So for example:

{1, "Yada"}, {2, "Data"} returns false
{1, "Yada"}, {1, "Data"} returns true

Can it be done?

It's the same premise - group by your key value and see how many groups have more then one element. — D Stanley, Mar 31 '16 at 15:49

score 1 · Answer 1 · answered Mar 31 '16 at 14:04

1

Just group by that value and see if any groups have more than one item:

bool hasDupes =
    list.GroupBy(t => t.Item1)
        .Any(g => g.Count() > 1)

answered Mar 31 '16 at 14:04

D Stanley

score 1 · Accepted Answer · answered Mar 31 '16 at 14:05

1

Yes it can be done by grouping:

bool match = list.GroupBy(tuple => tuple.Item1, t => t).Any(group => group.Count() > 1);

answered Mar 31 '16 at 14:05

René Vogt

2 Answers2