Concatenate string properties of an object with lambda

Question

Please consider the following:

public class MyObject {    public bool B;    public string Txt; }  List<MyObject> list; //list of a bunch of MyObject's  

With lambda expression, how can I produce a string consisting of comma separated values of Txt of those objects, where B is true?

Thank you.

Answer 1

for .net 3.5:

string.Join(",", list.Where(o => o.B).Select(o => o.Txt).ToArray()) 

for .net 4.0:

string.Join(",", list.Where(o => o.B).Select(o => o.Txt)) 

Answer 2

string myString = string.Join(",", list.Where(x => x.B).Select(x=>x.Txt));