How can I get value from object in sub-collection with lambda

Question

I have this code:

class A
{ 
public string Prop1;
public string Prop2;
public List<B> Prop3;
}

class B
{ 
public string Value1;
public int Value2;
public double Value3;
}

and have List of A and I neeed to get Value1 from B if Value2 from B equals to some string. I'd like to use lambda. How can I get it?

Here is the code when I use foreach:

//I have listA of type List<A>

foreach(var a in listA)
{
   foreach(bar b in a.Prop3
   {
      if(b.Value1=="some string")
      {
          return b.Value2;
      }
   }
}

How to use lambda without foreach?

Answer 1

You can do something like this:

 return listA
    .Select(a => 
        a.Prop3.FirstOrDefault(b => b.Value1 == "some string"))
    .FirstOrDefault();