CODEWITHSUNDEEP
c#.netgenerics
Jon
Jon

Reputation: 40032

Checking each item in IEnumerable<List<int>>

At the moment I have some code like below which based on a NoOfRows properties returns whether all data has been entered into list(s):

switch (NoOfRows)
            {
                case 1:
                    return InputList1.Any();
                case 2:
                    return InputList1.Any() && InputList2.Any();
                case 3:
                    return InputList1.Any() && InputList2.Any() && InputList3.Any();
                case 4:
                    return InputList1.Any() && InputList2.Any() && InputList3.Any() && InputList4.Any();
                case 5:
                    return InputList1.Any() && InputList2.Any() && InputList3.Any() && InputList4.Any() && InputList5.Any();
                case 6:
                    return InputList1.Any() && InputList2.Any() && InputList3.Any() && InputList4.Any() && InputList5.Any() && InputList6.Any();
                case 7:
                    return InputList1.Any() && InputList2.Any() && InputList3.Any() && InputList4.Any() && InputList5.Any() && InputList6.Any() && InputList7.Any();
                case 8:
                    return InputList1.Any() && InputList2.Any() && InputList3.Any() && InputList4.Any() && InputList5.Any() && InputList6.Any() && InputList7.Any() && InputList8.Any();
                case 9:
                    return InputList1.Any() && InputList2.Any() && InputList3.Any() && InputList4.Any() && InputList5.Any() && InputList6.Any() && InputList7.Any() && InputList8.Any() && InputList9.Any();
                case 10:
                    return InputList1.Any() && InputList2.Any() && InputList3.Any() && InputList4.Any() && InputList5.Any() && InputList6.Any() && InputList7.Any() && InputList8.Any() && InputList9.Any() && InputList10.Any();
                default:
                    return false;
            }

I'm thinking it might be better to refactor this code and have an List<List<int>> or a Dictionary<int,List<int>> but how would I do the above to return whether each list in the collection has something in it?

List<List<int>> values = new List<List<int>>(){InputList1, InputList2 ... InputList10};
var lists = values.Take(NoOfRows);
lists.. //check each item and return value of Any for each one

Upvotes: 2

Views: 179

Answers (5)

James Michael Hare
James Michael Hare

Reputation: 38397

If you just want to know if any sub-list is empty, try this:

var values = new List<List<int>>();  // create and load up...

...

// returns true if any sub-list is EMPTY
var isAnyEmpty = values.Any(l => !l.Any());

This will check if there exists any list in the list of lists that does not have an item.

However, if you want the indexes of those sub-lists that are empty, you can just store the results of the Any() on all:

// will return a lists of bools for Any() applied to each sub-list
var listStates = values.Select(l => l.Any()).ToList();

Then, the index of any result where the value is false will be a list without any items. Or, alternatively, you could use the special form of Select that pass along indexes directly.

Upvotes: 6

StaWho
StaWho

Reputation: 2488

Do you mean something like this:

        List<List<int>> list = new List<List<int>>();
        bool anyNonEmpty = list.Any(x => x.Any());

Upvotes: 0

Khan
Khan

Reputation: 18142

You may want to try something like this:

    bool ContainsEmptyCollection(IEnumerable<List<int>> collections)
    {
        foreach (var collection in collections)
        {
            if (collection.Count == 0)
                return true;
        }

        return false;
    }

Upvotes: 0

Matthew Walton
Matthew Walton

Reputation: 9959

var listoflists = new List<List<int>>;
bool allNonEmpty = listoflists.All(list => list.Any());

Upvotes: 1

McKay
McKay

Reputation: 12604

having nested lists can work well. you might want to look into the use of selectmany

but I think the code you want is something like:

var nested = new List<List<int>>();
// put data in it

nested.All((inner) => inner.Any());

Upvotes: 4

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