CODEWITHSUNDEEP
c#arrayslinqpropertiesnested
Tony Rush
Tony Rush

Reputation: 329

Linq Query to Return Nested Arrays having specific Property Value

I've been scouring multiple resources and can't figure this one out; I am trying to filter an Array of objects based on a Property that is nested a couple levels deep. I've simplified things, so let's say I have the following classes:

class A {
  B[] bb;
}

class B 
  C[] cc;
}

class C {
  string value;
}

And now the code:

A[] aa = ...;
A[] filteredAa = aa.Where(... //NEED HELP HERE

What I want to do is filter the aa array such that it gives me only those A elements that have at least one B element that have at least one C element has a value of "hello" (e.g. aa[0] would be included in the filteredAa array if aa[0].bb[3].cc[2].value = "hello").

Can this type of filtering even be done? I think and hope this makes sense, but please let me know if I can clarify any further.

Upvotes: 2

Views: 6996

Answers (4)

Uchiha_Sasuke
Uchiha_Sasuke

Reputation: 309

filteredAa = aa.Where(x => x.bb.Any(y => y.cc.Any(z => z.value == "hello")))

Upvotes: 0

Jon Skeet
Jon Skeet

Reputation: 1499800

You need to use Any - and it sounds like you need to use it twice:

var query = aa.Where(a => a.bb.Any(b => b.cc.Any(c => c.value == "hello")));

So working up from the inside:

  • A C object is useful if its value is "hello"
  • A B object is useful if any of its C values are useful
  • An A object is useful if any of its B values are useful
  • Where filters a sequence of A objects, leaving only the useful ones

You can use ToArray() at the end if you really want an array, but I would typically use ToList or just keep it as an IEnumerable<A>.

Upvotes: 4

Servy
Servy

Reputation: 203802

If you are looking for where Value is a specific value:

var result = aa.Where(a=>a.bb.Any(b => b.cc.Any(c => c.Value == "hello"));

If you just want to get all of those that have any value:

var result = aa.Where(a=>a.bb.Any(b => b.cc.Any(c => !string.IsNullOrEmpty(c.Value)));

Upvotes: 0

cdhowie
cdhowie

Reputation: 168958

Try this:

A[] filteredAa = aa.Where(a => a.bb.Any(b => b.cc.Any(c => c.value == "hello"))).ToArray();

Upvotes: 1

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