C# Tips: Loops and iterators in c# (5 ways).

It is suggested to inspect several ways to implement loop in c#.

For example, we need display all days: Sunday .. Saturday with help of loop (or iterators).

Operator For:

static void sample_For_Days()
{
    for (int index = 0; index < DaysNames.DAYS.Length; index++)
    {
        string day = DaysNames.DAYS[index];
        Console.Write(day + " ");
    }
    Console.WriteLine();
}

Operator foreach:

foreach (string day in DaysNames.DAYS)
{
    Console.Write(day + " ");
}
Console.WriteLine();

Method Array.Foreach:

Array.ForEach(DaysNames.DAYS, 
    delegate(string day) { Console.Write(day + " "); });
Console.WriteLine();

Operator ForEach with help of interfaces IEnumerable and IEnumerator

class implementation

public class DaysOfTheWeek_IEnumerator : IEnumerable, IEnumerator
{
    int index;
    public DaysOfTheWeek_IEnumerator()
    {
        Reset();
    }
    #region IEnumerable
    public IEnumerator GetEnumerator()
    {
        return this;
    }
    #endregion

    #region IEnumerator
    public bool MoveNext()
    {
        return (++index < 7);
    }
    public void Reset()
    {
        index = -1;
    }
    public object Current
    {
        get { return DaysNames.DAYS[index]; }
    }
    #endregion
}

usage of foreach

DaysOfTheWeek_IEnumerator week = new DaysOfTheWeek_IEnumerator();

foreach (string day in week)
{
    Console.Write(day + " ");
}
Console.WriteLine();

Operator ForEach with help of interfaces IEnumerable and statement yield:

class implementation:

public class DaysOfTheWeek_yield : IEnumerable
{
    #region IEnumerable
    public IEnumerator GetEnumerator()
    {
        for (int i = 0; i < DaysNames.DAYS.Length; i++)
        {
            yield return DaysNames.DAYS[i];
        }
    }
    #endregion
}

usage of foreach:

DaysOfTheWeek_IEnumerator week = new DaysOfTheWeek_IEnumerator();

foreach (string day in week)
{
    Console.Write(day + " ");
}
Console.WriteLine();