How to calculate total in arrayList

[Jackwaters]

I have a problem in that I have an arrayList called pizzaOrders which contains a number of pizza orders. The pizza orders contain information like names, addresses, total price for orders and the dates of orders.

The date is selected through a dateTimePicker. Basically what I need to do is count the orders on a particular day and produce a graph for this.

So I need, for example, to search the arrayList and calculate how many orders were made on each day. I assume this is done by totalling the number of times Monday appears in the arrayList to give me a figure.

Any help would be great, I've been trying hard but to no avail.

Thanks

Jack

[Christopher Nigro]

Can you ditch the array list and use a List<PizzaOrder> instead? If so, you could do something similiar to this:

List<PizzaOrder> orders = new List<PizzaOrder>();
orders.Add(new PizzaOrder("Customer A", new DateTime(2010, 7, 1, 12, 5, 0), (decimal)19.95d));
orders.Add(new PizzaOrder("Customer B", new DateTime(2010, 7, 1, 13, 30, 0), (decimal)6.99d));
orders.Add(new PizzaOrder("Customer C", new DateTime(2010, 7, 2, 11, 45, 0), (decimal)42.80d));
orders.Add(new PizzaOrder("Customer D", new DateTime(2010, 7, 3, 04, 0, 0), (decimal)10.00d));
 
decimal dayTotal = (from o in orders where o.OrderDate.DayOfWeek == DayOfWeek.Thursday select o.Total).Sum();
 
Console.WriteLine(string.Format("The total for Thursday is: {0}", dayTotal));
 

[Jackwaters]

How would I use it to display the total number of orders on say Monday. I don't want the total for that day just the total number of orders.

For example (using your code):

orders.Add(new PizzaOrder("Customer A", new DateTime(2010, 7, 1, 12, 5, 0), (decimal)19.95d));
orders.Add(new PizzaOrder("Customer B", new DateTime(2010, 7, 1, 13, 30, 0), (decimal)6.99d));
orders.Add(new PizzaOrder("Customer C", new DateTime(2010, 7, 2, 11, 45, 0), (decimal)42.80d));
orders.Add(new PizzaOrder("Customer D", new DateTime(2010, 7, 3, 04, 0, 0), (decimal)10.00d));
 

To produce the result that 2 orders were made on Thursday? At the moment it is displaying the total price.

Thanks,

Jack

[Christopher Nigro]

Ah, sorry about that! I misread your original post. All you need to do is change that one line to this:

int dayTotal = (from o in orders where o.OrderDate.DayOfWeek == DayOfWeek.Thursday select o.Total).Count();

I assume you are using Visual Studio - if so, delete that last '.' before Count() and then retype it - IntelliSense will pop up and show you all of the goodies that are available.

[Jackwaters]

Works perfectly, thank you.