C# comparing two object values

Question

I have 2 List objects.

private static List<Logs> _logsDutyStatusChange = new List<Logs>();
private static List<Logs> _logsNonDutyStatusChange = new List<Logs>();

Both of these lists contain a driverid and a date.

I need to see which driverid's are in _logsNonDutyStatusChange that are also in _logsDutyStatusChange.

If they are in _logsNonDutyStatusChange, then replace the date in _logsDutyStatusChange with the MaxDate in _logsNonDutyStatusChange.

How would I go about this. Right now I have the following(does not work):

 foreach (Logs log in _logsDutyStatusChange)
            {
                if (_logsNonDutyStatusChange.Contains(log.did))
                {

                }

            }

What is your approach? share what you've already done? and where exactly you need help? — Sanjeevakumar Hiremath
– Sanjeevakumar Hiremath, Commented Apr 18, 2011 at 16:01
I have populated the list objects through web service calls using linq. I need help with comparing the data between the 2 objects then populating the _logsDutyStatusChange with the other objects data if the driver id exists. — user380432
– user380432, Commented Apr 18, 2011 at 16:04

František Žiačik · Accepted Answer · 2011-04-18 16:07:42Z

4

If you can use Linq:

var lookup = _logsNonDutyStatusChange.ToLookup(l => l.did);

foreach (Logs log in _logsDutyStatusChange)
{
    if (lookup.Contains(log.did))
    {
        var maxDate = lookup[log.did].Max(l => l.date);
        log.date = maxDate;
    }
}

answered Apr 18, 2011 at 16:07

František Žiačik

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Comments

Daniel A. White · Accepted Answer · 2011-04-18 16:02:35Z

3

You could implement IEquatable<T>

answered Apr 18, 2011 at 16:02

Daniel A. White

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Comments

Aliostad · Accepted Answer · 2011-04-18 16:11:39Z

1

Try this if you want to do it purely the Linq way

  _logsDutyStatusChange.Where(x=> _logsNonDutyStatusChange.Any(y=>y.DriveId == x.DriveId))
            .ToList().ForEach(xx => xx.Date = _logsNonDutyStatusChange.Where(yy=>yy.DriveId==xx.DriveId)
            .Max(yyy=>yyy.Date));

edited Apr 18, 2011 at 16:11

answered Apr 18, 2011 at 16:05

Aliostad

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Comments

Bala R · Accepted Answer · 2011-04-18 16:05:35Z

0

You can try

 foreach (Logs log in _logsDutyStatusChange)
 {


    if (_logsNonDutyStatusChange.Select (l => l.did).Contains(log.did))
    {

    }

 }

answered Apr 18, 2011 at 16:05

Bala R

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Comments

JSBձոգչ · Accepted Answer · 2011-04-18 16:08:58Z

0

If you must use for-loops, you need this:

foreach (Logs log in _logsDutyStatusChange)
{
    foreach (var nonDutyLog in _logsNonDutyStatusChange)
    {
        if (nonDutyLog.did.Equals(log.did))
        {
            // do something
        }
    }
}

But note that this is O(n*m), which is expensive, particularly if you have a lot of entries. If you need something like this, you'll be better of converting some of these lookups into hash tables. The quick and easy way to do this is with ToLookup():

var nonDutyLookup = _logsNonDutyStatusChange.ToLookup(log => log.did, log => log);

foreach (Logs log in _logsDutyStatusChange)
{
    foreach (matchingLog in nonDutyLookup[log.did])
    {
        // handle the matching log
    }
}

edited Apr 18, 2011 at 16:08

answered Apr 18, 2011 at 16:03

JSBձոգչ

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