String Comparison Troubles

Question

Let me start by saying that I have read up on my problem, specifically this question and this one also. My problem is a little different, however. I understand the differences between the different methods, but cannot get my code to run correctly for the life of me.

In part of my code, I have the comparison below. But the comparison always fails, and "Type is:leg" prints out.

if (String.Compare(timer.Type,"leg",true) == 0)
{
    timer.StopTime = DateTime.Now;
    // TODO Log into database here
    toRemove.Add(timer);
}
//Couple more conditions in here...
else
{
    Console.WriteLine("Attempting to remove cycle timer of invalid type");
    Console.WriteLine("Type is:" + timer.Type);
//TODO: Log error
}

I also tried alternative methods, but none of them seem to work for me.

if(timer.Type == "leg" || timer.Type == "Leg") //Fails

if(time.Type.Equals("leg") || timer.Type == "Leg") //Fails

String type = timer.Typer; //Worth a shot...
if(type == "leg" || type == "Leg") //No luck

EDIT: More code has been requested, so here is the entire method.

private void stopFinishedTimers(AGVData agv)
{
    List<CycleTimer> toRemove = new List<CycleTimer>();

    foreach (CycleTimer timer in AllRunningCycleTimers)
    {
        if (agv.CurrentRFIDNumber == timer.CycleStopRfid)
        {
            if (String.Compare(timer.Type,"leg",true) == 0)
            {
                timer.StopTime = DateTime.Now;
                // TODO Log into database here
                toRemove.Add(timer);
                }
            else if (timer.Type.Equals("route") || timer.Type.Equals("Route"))
            {
                timer.StopTime = DateTime.Now;
                // TODO Log into database here
                toRemove.Add(timer);
            }
            else
            {
                Console.WriteLine("Attempting to remove cycle timer of invalid type");
                Console.WriteLine("Type is:" + timer.Type);
                //TODO: Log error
            }
        }
    }

Where CycleTimers are a class containing a fields called type, accessed through a property.

Where does the CycleTimer come from ? is this one of your own classes ? Do you use some special framework ? — Bongo, Jul 20 '15 at 19:58
@JShell Thanks for your update. However still, the definition of `CycleTimer` is missing. — BartoszKP, Jul 20 '15 at 20:00
@JohnCarpenter `StringComparison.Ordinal` fixed it, thanks a million — JShell, Jul 20 '15 at 20:14
@JShell had you provided executable code this issue would have been found immediately. Could have been `"lag" == "Lag"` or something simple like that. — usr, Jul 20 '15 at 20:23
@JShell that's just a 20 character code snippet. Just capture the problematic strings with the debugger and paste them here. — usr, Jul 20 '15 at 20:35

Frank Bryce · Accepted Answer · 2015-07-21T14:42:39.787

I'll add my two cents:

The line String type = timer.Typer seems wrong because the property name is Type in most of your examples. Also if(time.Type.Equals("leg") || timer.Type == "Leg") seems suspicious since you are referencing time and timer instead of the same variable both times.

Lastly, I always always use StringComparison.Ordinal when comparing strings in .Net because of culture info and character set differences, etc. I'm not sure if that could be an issue but see this for more information.

EDIT:

On a side note, StringComparison.OrdinalIgnoreCase is also an option.

GreatJobBob · Answer 2 · 2015-07-21T00:30:53.610

1

Debug and put a break statement to see what timer.Type equates to, or put a Console.WriteLine(timer.Type.ToString())... Could timer have gone out of scope?

or maybe change the test to timer.Type.ToString() == "Leg"

edited Jul 21 '15 at 00:30

answered Jul 21 '15 at 00:25

GreatJobBob

271
1
8

== doesn't work that well on strings, Equals() method is always better. – David Gomes Jul 29 '15 at 11:17

String Comparison Troubles

2 Answers2