IEnumerable in C#

<%@ Page Language="C#" AutoEventWireup="true" CodeBehind="Default.aspx.cs" Inherits="IEnumerableInterface.Default" %>  
  
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">  
<html xmlns="http://www.w3.org/1999/xhtml">  
<head runat="server">  
    <title></title>  
</head>  
<body>  
    <form id="form1" runat="server">  
   
    <asp:Button ID="Button1" runat="server" Text="GetList" OnClick="Button1_Click" />  
    </form>  
</body>  
</html> 

Now open the Default.aspx.cs class file and create class named Customer with properties as:

public class Customer  
{
    private String _Name, _City;  
    private long _Mobile;  
    private double _Amount;  
 
    public String Name  
    {  
        get { return _Name; }  
        set { _Name = value; }  
    }  
    public String City  
    {  
        get { return _City; }  
        set { _City = value; }  
    }  
 
    public long Mobile  
    {  
        get { return _Mobile; }  
        set { _Mobile = value; }  
     }
  
    public double Amount  
    {  
        get { return _Amount; }  
        set { _Amount = value; }  
    }  
}

In the above class file we have created properties of type string, long and double which later on we will use along with IEnumerable generic interface. Now create the Array of type customer class and assign the values to each property as:

Customer[] customers = new Customer[]  
{
    new Customer {Name="Vithal Wadje",City="Mumbai",Mobile=99999999999,Amount=89.45 },  
    new Customer { Name = "Sudhir Wadje", City = "Latur", Mobile = 88888888888888888888, Amount =426.00 },  
    new Customer { Name = "Anil", City = "Delhi", Mobile = 77777777777777777777, Amount = 5896.20 } 
};

Now in the above, customer type array has different types of values we have assigned to the properties that we have created, now let us use the IEnumerable interface loop through above collection as:

public IEnumerable<Customer> GetAllCustomer()  
{  
    return customers;                    
} 

In the above example I have assigned the Customer class collection to the IEnumerable to loop through each element, now we have already explained that IEnumerable interface collection can be iterated with the help of foreach loop over the IEnumerable interface collection, now let iterate through each item using IEnumerable interface as

foreach (var cust in GetAllCustomer())  
{      
    Response.Write("Name: "+cust.Name + " 
    <br> " +"City: " +cust.City + " <br> " +"Mobile "+cust.Mobile+"<br>
    "+"Amount :" +cust.Amount.ToString("c") + "<br>"+"-----"+"<br>"); 
}

In the above code, we are iterating on each item contained in the GetAllCustomer() collection IEnumerable interface method, now the whole code will look like the following:

using System;  
using System.Collections.Generic;  
  
namespace IEnumerableInterface  
{  
    public partial class Default : System.Web.UI.Page
    {
        protected void Page_Load(object sender, EventArgs e)
        {
        }
        protected void Button1_Click(object sender, EventArgs e)
        {
            foreach (var cust in GetAllCustomer())
            {
              Response.Write("Name: "+cust.Name + "<br> " +"City: " +cust.City + " <br> "
                        +"Mobile "+cust.Mobile+"<br> "+"Amount :" +cust.Amount.ToString("c") + "<br>"+"-----"+"<br>");
            }
        }
        public class Customer  
        {
            private String _Name, _City;  
            private long _Mobile;  
            private double _Amount;  
  
            public String Name  
            {  
                get { return _Name; }  
                set { _Name = value; }  
            }  
            public String City  
            {  
                get { return _City; }  
                set { _City = value; }  
            }  
  
            public long Mobile  
            {  
                get { return _Mobile; }  
                set { _Mobile = value; }  
            }
            public double Amount  
            {  
                get { return _Amount; }  
                set { _Amount = value; }  
            }
        }  
        Customer[] customers = new Customer[]  
        {  
  
            new Customer {Name="Vithal Wadje",City="Mumbai",Mobile=99999999999,Amount=89.45 },  
            new Customer { Name = "Sudhir Wadje", City = "Latur", Mobile = 88888888888888888888, Amount =426.00 },  
            new Customer { Name = "Anil", City = "Delhi", Mobile = 77777777777777777777, Amount = 5896.20 }
        };  
  
        public IEnumerable<Customer> GetAllCustomer()  
        {
            return customers;
        }
    }  
}

Now run the application and click on GetList button and the output will be as follows:

Now from the above example, it's clear that we can iterate through generic as well as non-generic collection with the help IEnumerable interface.

Notes

• Download the Zip file from the attachment for the full source code of the application.

Summary

I hope this article is useful for all readers, if you have any suggestions then please contact me, even if you're a beginner.