Provide different IEnumerable implemetation for one class : IEnumerable « Data Structure « C# / CSharp Tutorial






using System;
using System.Collections.Generic;

public class Employee
{
    public string Name;
    public string Title;

    public Employee(string name, string title)
    {
        Name = name;
        Title = title;
    }

    public override string ToString()
    {
        return string.Format("{0} ({1})", Name, Title);
    }
}

public class EmployeeList 
{
    private List<Employee> employeeList = new List<Employee>();

    public IEnumerator<Employee> GetEnumerator()
    {
        foreach (Employee tm in employeeList)
        {
            yield return tm;
        }
    }

    public IEnumerable<Employee> Reverse
    {
        get
        {
            for (int c = employeeList.Count - 1; c >= 0; c--)
            {
                yield return employeeList[c];
            }
        }
    }

    public IEnumerable<Employee> FirstTwo
    {
        get
        {
            int count = 0;

            foreach (Employee tm in employeeList)
            {
                if (count >= 2)
                {
                    yield break;
                }
                else
                {
                    count++;
                    yield return tm;
                }
            }
        }
    }

    public void AddEmployee(Employee member)
    {
        employeeList.Add(member);
    }
}

public class MainClass
{
    public static void Main()
    {
        EmployeeList employeeList = new EmployeeList();
        employeeList.AddEmployee(new Employee("A", "AA"));
        employeeList.AddEmployee(new Employee("B", "BB"));
        employeeList.AddEmployee(new Employee("C", "CC"));

        
        Console.WriteLine("Enumerate using default iterator:");
        foreach (Employee member in employeeList)
        {
            Console.WriteLine("  " + member.ToString());
        }

        Console.WriteLine("Enumerate using the FirstTwo iterator:");
        foreach (Employee member in employeeList.FirstTwo)
        {
            Console.WriteLine("  " + member.ToString());
        }

        Console.WriteLine("Enumerate using the Reverse iterator:");
        foreach (Employee member in employeeList.Reverse)
        {
            Console.WriteLine("  " + member.ToString());
        }
    }
}
Enumerate using default iterator:
  A (AA)
  B (BB)
  C (CC)
Enumerate using the FirstTwo iterator:
  A (AA)
  B (BB)
Enumerate using the Reverse iterator:
  C (CC)
  B (BB)
  A (AA)








11.43.IEnumerable
11.43.1.Implement IEnumerable with 'yield'
11.43.2.Implement IEnumerable with loop
11.43.3.Provide different IEnumerable implemetation for one class
11.43.4.yield value for IEnumerable
11.43.5.Get list of integer whose value is higher than 10
11.43.6.Iterator Block Iteration Sample
11.43.7.Counting Enumerable