Is it possible to do list manipulation using LINQ?

Question

This may be a stupid question but I've always used linq to select items.

But i wish to know if it possible to do the following simple task using its keywords.

List<OrdersInfo> ordersList
.
.
.
foreach(OrdersInfo OI in ordersList)
        if(OI.TYPE == "P")
            OI.TYPE = "Project";
        else
        OI.TYPE = "Support";

Answer 1

You can use ForEach method of List class.

ordersList.ForEach(oi => oi.TYPE = oi.TYPE == "P" ? "Project" : "Support" );

If you want have ForEach method in IEnumerable type you can create your own ForEach extension

public static void ForEach<T>(this IEnumerable<T> en, Action<T> action)
{
    foreach(T item in en)
    {
        action(item);
    }
}

Answer 2

No, LINQ(Language-Integrated Query) is a query language and it really shines in consise query definition, but not always good in that too (speed and/or memory concerns).

If you want to modify collection, stay with the way you already do that.

Answer 3

LINQ is for querying collection, For modification your current loop is more readable and better approach, but if you want LINQ option then:

If OrderInfo is a class (reference type), then you can modify the properties of the object, (You can't assign them null or a new references).

var ordersList = new List<OrdersInfo>();
ordersList.Add(new OrdersInfo() { TYPE = "P" });
ordersList.Add(new OrdersInfo() { TYPE = "S" });
ordersList.Add(new OrdersInfo() { TYPE = "P" });
ordersList.Select(r => (r.TYPE == "P" ? r.TYPE = "Project" : r.TYPE = "Support")).ToList();

With Your class defined as:

class OrdersInfo
{
    public string TYPE { get; set; }
}

Here is the screenshot

Interestingly I didn't assign the result back to ordersList