CODEWITHSUNDEEP
vb.netlistdictionaryforeachcontains
Samuel Cabrera
Samuel Cabrera

Reputation: 73

How to check for value in a list of dictionaries in vb.net?

What expression can return a boolean if any dictionary within a list contains a particular value?

Imagine this, but without having to reference each item in the list individually:

(Dict_List(0).ContainsValue(value) or Dict_List(1).ContainsValue(value) or Dict_List(2).ContainsValue(value))=False

Ideally, if the value is not already in one of the dictionaries, along with several other conditions; then the code would add another dictionary. I know a foreach might work in this case, but a single expression would be faster at runtime, and it would be nice to know this just as a best practice.

Upvotes: 0

Views: 1419

Answers (1)

jmcilhinney
jmcilhinney

Reputation: 54417

There are two LINQ options that come to mind:

If Dict_List.SelectMany(Function(d) d.Values).Contains(value) Then

or:

If Dict_List.Any(Function(d) d.ContainsValue(value)) Then

The first option gets the values from each Dictionary and concatenates them all into a single list, then checks that list for a matching value. The second option checks each Dictionary individually and returns True if any individual check returns True. Being LINQ, they both avoid pointlessly checking the rest of the values if a match is found.

Upvotes: 2

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