string AllPDF = "";
int CountPDF = 0;
AllPDF = txtInput.Text;
string[] AllPDF2 = AllPDF.Split(';');
List<string> PDF = new List<string>();
PDF.AddRange(AllPDF2);
while (PDF.Count != CountPDF)
{
    File.Delete(AllPDF2[0 + CountPDF] + ".pdf");
	CountPDF++;
}

const int ONLY_ONE_ITEM = 1;

if (myList.Count > ONLY_ONE_ITEM)
{
    DoSomething();
}
else
{
    DoSomethingElse();
}

// Return flagged enum with inverted selected flag value
public static TEnum SwapFlag<TEnum>(this TEnum target, TEnum flag) where TEnum : Enum
    {
        if (target.HasFlag(flag)) return (TEnum)(object)((int)(object)target & ~(int)(object)flag);

        return (TEnum)(object)((int)(object)target | (int)(object)flag);
    }

 if (!String.IsNullOrEmpty(Client.CLADDR1))
            {
                if (Client.CLADDR1 == "NULL")
                {

// IsFooBar being a boolean, we check if it's different from true and from false
if (x.IsFooBar != true && x.IsFooBar != false)
{
    return "error";
}

private readonly FooType _foo = new FooType();

/// <summary>
/// Gets the controller of this component
/// </summary>
private FooType Foo
{
    get
    {
        return _foo;
    }
}

namespace network
{
    class ip
    {
        uint _IP;
        public ushort this[int i]
        {
            get
            {
                switch(i)
                {
                    case 0:
                    case 1:
                    case 2:
                    case 3:
                        return (ushort)(_IP>>(i*8));
                    default:
                    throw new IndexOutOfRangeException();
                }
            }
            set
            {
                switch(i)
                {
                    case 0:
                    case 1:
                    case 2:
                    case 3:
                        _IP=(((uint)value)<<i*8);
                        break;
                    default:
                    throw new IndexOutOfRangeException();
                }
            }
        }
    }
}

var list = new List<string>() { // Assume some items in the list };

for (var i = 0; i < list.Count; i++)
{
    var item = list[i];
    list.Remove(item);
    
    i--;
}

public static class time
{
    public const int minutes_per_hour = 60;
    public const int seconds_per_minute = 60;
    public const int hours_per_day = 24;
    public const int minutes_per_day = minutes_per_hour * hours_per_day;
    public const int seconds_per_day = seconds_per_minute * minutes_per_day;
    public const int days_per_year = 365;
}

/// <summary>
/// Returns true if any component of of Vector3 v is negative
/// </summary>
public static bool Ext_IsNegative(this Vector3 v)
{
    return v.x < 0f && v.y < 0f && v.z < 0f;
}

public class MetricsChecker
{
    protected const string AwaitingRecognitionCountMetricName = "AwaitingRecognitionCount";
    protected const string AwaitingExportCountMetricName = "AwaitingExportCount";
    protected const string NotYetDownloadedEventCountMetricName = "NotYetDownloadedEventCount";
    
    ...
    
    public virtual void PublishNotYetDownloadedEventCounts()
    {
        this.logger.Trace($"Starting to gather and publish {NotYetDownloadedEventCountMetricName}(s).");
        ...
    }
    
    ...
}

        protected override void OnStartup(StartupEventArgs e)
        {
            Current.DispatcherUnhandledException += ApplicationUnhandledException;

            base.OnStartup(e);

#if (DEBUG)
            RunInDebugMode(e.Args);
#else
            RunInReleaseMode(e.Args);
#endif
        }

#endregion

        private static void RunInReleaseMode(string[] args)
        {
            AppDomain.CurrentDomain.UnhandledException += AppDomainUnhandledException;

            try
            {
                SplashScreen screen = new SplashScreen(@"Images\splashscreen.png");
                screen.Show(true, true);

                RunInDebugMode(args);
            }
            catch (Exception ex)
            {
                HandleException(ex);
            }
        }

        private static void RunInDebugMode(string[] args)
        {
            var bootstrapper = new Bootstrapper();
            bootstrapper.Run();
        }

if (date.Training != null)
            {
                var training = date.Training;
                var status = new TrainingStatus();
                var refresher = new Training();

                if (training.Trainings != null)
                    refresher = training.Trainings;

                bool hasTakenRefresher = false;
                status.Value = date.Date.AddDays(
                    TrainingHelper.CalculateValidityDays(training.Validity ?? 0, training.ValidityType ?? 0));

                status.Name = training.TrainingName;
                status.ID = training.TrainingID;
                status.Category = training.CategoryTraining != null ? training.CategoryTraining.Name : "Other";
                status.IsTrained = _validityUtilsService.IsValid(training, date.Date);

                if (status.IsTrained)
                {
                    status.IsExpiring = _validityUtilsService.IsExpiring(training, date.Date,
                                            TrainingHelper.CalculateValidityDays(
                                                training.ExpirationWarningValidity ?? 0,
                                                training.ExpirationWarningValidityType ?? 0));
                }

                if (refresher.ID != 0)
                {
                    hasTakenRefresher = employee.Dates
                        .Count(x => x.Training != null
                            && x.TrainingID == refresher.ID) > 1;

                    if (hasTakenRefresher && (status.IsExpiring || !status.IsTrained))
                    {
                        status.IsExpiring = false;
                        var trainingWithNewValidity = new Training();

                        status.Value = date.Date.AddDays(
                            TrainingHelper.CalculateValidityDays(training.ValidityRefresher ?? 0,
                                training.ValidityRefresherType ?? 0));

                        trainingWithNewValidity.Validity = training.ValidityRefresher;
                        trainingWithNewValidity.ValidityType = training.ValidityRefresherType;
                        status.IsTrained = _validityUtilsService.IsValid(trainingWithNewValidity, date.Date);

                        if (status.IsTrained)
                        {
                            status.IsExpiring = _validityUtilsService.IsExpiring(trainingWithNewValidity, date.Date,
                                TrainingHelper.CalculateValidityDays(
                                    refresher.ExpirationWarningValidity ?? 0,
                                    refresher.ExpirationWarningValidityType ?? 0));
                        }
                    }
                }

                if (status.IsTrained && !status.IsExpiring)
                    status.Status = TrainingStatuses.Trained;
                else if (status.IsTrained && status.IsExpiring)
                    status.Status = TrainingStatuses.Expiring;
                else if (!status.IsTrained && !status.IsExpiring)
                    status.Status = TrainingStatuses.Expired;

                status.EmpID = employee.ID;

                return status;
            }

        /// <summary>
        /// Builds the suffixs for the request sequence number
        /// </summary>
        /// <param name="i"></param>
        /// <returns></returns>
        public static string GetSequenceNumber(int i)
        {
            string strCount = string.Empty;
            string increase = string.Empty;
            int count;
            strCount = i.ToString();
            count = strCount.Length;
            //Add 0 infront of the index to make a 4 digit number
            if (count < 5)
            {
                for (int j = 0; j < (4 - count); j++)
                {
                    increase = increase + "0";
                }
                strCount = increase + strCount;
            }
            return strCount;
        }

    public static class DecimalHelpers
    {
        /// <summary>
        /// Format a decimal XX.XX to XX,XX%.
        /// </summary>
        /// <param name="value"></param>
        /// <returns></returns>
        public static string FormatToStringPercentageValue(this decimal value)
        {
            return value.ToString().Replace(".", ",").FormatToPercentageValue();
        }
    }
    
    public static class StringHelpers
    {
        /// <summary>
        /// Add % at the end of the string.
        /// </summary>
        /// <param name="value"></param>
        /// <returns></returns>
        public static string FormatToPercentageValue(this string value)
        {
            return string.Concat(value, "%");
        }
    }