Reputation: 20140
from a list, which got 3 attributes I want to return a new list of that class where attribut1 recurrence in the list equals X
for an example this;
1,a,b
1,c,d
1,e,f
2,a,b
2,c,d
3,a,b
3,c,d
3,e,f
4,a,b
5,a,b
5,c,d
5,e,f
6,a,b
6,e,f
where X = 1 would return that list
4,a,b
where X = 2 would return that list
2,a,b
2,c,d
6,a,b
6,e,f
where X = 3 would return that list
1,a,b
1,c,d
1,e,f
3,a,b
3,c,d
3,e,f
5,a,b
5,c,d
5,e,f
Upvotes: 3
Views: 377
Reputation: 74949
public static void Test()
{
var list = new[]
{
new {p1 = 1, p2 = 'a', p3 = 'b'},
new {p1 = 1, p2 = 'c', p3 = 'd'},
new {p1 = 1, p2 = 'e', p3 = 'f'},
new {p1 = 2, p2 = 'a', p3 = 'b'},
new {p1 = 2, p2 = 'c', p3 = 'd'},
new {p1 = 3, p2 = 'a', p3 = 'b'},
new {p1 = 3, p2 = 'c', p3 = 'd'},
new {p1 = 3, p2 = 'e', p3 = 'f'},
new {p1 = 4, p2 = 'a', p3 = 'b'},
new {p1 = 5, p2 = 'a', p3 = 'b'},
new {p1 = 5, p2 = 'c', p3 = 'd'},
new {p1 = 5, p2 = 'e', p3 = 'f'},
new {p1 = 6, p2 = 'a', p3 = 'b'},
new {p1 = 6, p2 = 'e', p3 = 'f'}
};
for (int i = 1; i <= 3; i++)
{
var items = from p in list
group p by p.p1
into g
where g.Count() == i
from gi in g
select gi;
Console.WriteLine();
Console.WriteLine("For " + i);
Console.WriteLine();
foreach (var x in items)
{
Console.WriteLine("{0},{1},{2}", x.p1, x.p2, x.p3);
}
}
}
Upvotes: 0
Reputation: 5256
Perfect case for grouping!
var groups = list.GroupBy(s => s.Attribute1);
var recur_1 = groups.Where(g => g.Count() == 1).SelectMany(s => s);
var recur_2 = groups.Where(g => g.Count() == 2).SelectMany(s => s);
var recur_3 = groups.Where(g => g.Count() == 3).SelectMany(s => s);
Upvotes: 3