Set or Assign a value in a Nested generic collection using LinQ C#

Question

I've a list of SelectedEmployees from list of Employees class in IEnumerable<Employee> SelectedEmployees collection. Again I've nested generic collection as below code. How can i set IsPhoneAssigned value to true for only selected employees using LinQ with C#

 public class Employee
    {
       IList<PhoneProperty> Phones {get; set;}
    }

public class PhoneProperty
    {
        public bool IsPhoneAssigned { get; set; }
    }

Answer 1

Linq is for querying, not for assignment. Thus, your implementation can be split into two parts:

1. Linq to select your Employee
2. For/Foreach loop to assign the property value into true

Something like this:

var query = SelectedEmployees.Where(x => myCondition(x));
foreach (var q in query)
    foreach (var p in q.Phones)
        p.IsPhoneAssigned = true;

Answer 2

var employeesList; // this is your list from context
foreach(var emp in employeesList) // iterate and change all phones 
{
    foreach(var ph in emp.Phones)
        ph.IsPhoneAssigned = true;
}
_context.SubmitChanges(); // save changes to context

I find another elegant way to solve your problem:

var changedCollection =  _context.SelectedEmployees.Select(x => 
    {
       x.Phones.Select(y => 
                      { 
                         y.IsPhoneAssigned = true;
                         return y;
                      })
    }).ToList();

_context.SubmitChanges();

Here you creating anonymouse function, that changes property of your object and return it with changed property. But actually i think 1 option is a way more readable and maintainable.