Saving output from "If statement" c#

Question

I have a conditional as such:

List<HWSRunSession> session = new List<HWSRunSession>();
foreach (var item in fileInfo)
{
    if(_db.HWSRunSessions.Where((x) => x.TransferredZipName == item.Name 
    && DateTime.Now.Subtract(x.AddedDate).TotalDays >= _ExpirationDays) == null) {
     bla bla...
    }        
}

But I want to save the list I retrieve in the conditional to my variable session using the "out" key word. kind of like:

List<HWSRunSession> session = new List<HWSRunSession>();
foreach (var item in fileInfo)
{
    if(_db.HWSRunSessions.Where((x) => x.TransferredZipName == item.Name 
    && DateTime.Now.Subtract(x.AddedDate).TotalDays >= _ExpirationDays), out session == null) {



    }
}

Is this possible and if so how?

Answer 1

The most readable and maintainable solution is to store the result in a variable, then test this variable in the condition:

var session = _db.HWSRunSessions
    .Where((x) => x.TransferredZipName == item.Name 
       && DateTime.Now.Subtract(x.AddedDate).TotalDays >= _ExpirationDays)
    .FirstOrDefault();
if(session == null)
{
  // session is null
}
else
{
  // do something with session
}

If you absolutely must assign a variable within an expression, it is possible. But it makes the code more difficult to read and easier to miss bugs:

Session session = null;
if ((session = _db.HWSRunSessions
    .Where((x) => x.TransferredZipName == item.Name 
        && DateTime.Now.Subtract(x.AddedDate).TotalDays >= _ExpirationDays)
    .FirstOrDefault()) == null)
{
  // session is null
}
else
{
  // do something with session
}