Remove an Item from C# Enum List

Question

I am storing a list of Choices of Enum values and my Enum looks like below

enum OrderDay 
{
    Sunday,
    Monday,
    Wednesday,
    Friday,
    Saturday
};
List<OrderDay> DayChoices;  //List stores the selected values

Initially the List contains 3 values

{
Wednesday,
Friday,
Saturday
}

How to filter out a specific value from this list and makes list as

{
    Wednesday,
    Friday
}

This is the code i was trying , but ended up as build error. Trying to recreate the list without the given day value

private async Task OnChipDayEnumClose(OrderDay val)
{ 
    DayChoices = DayChoices.Where(s => s != val).ToList();
}

`List` has a `RemoveAll` method that takes in a predicate... you don't need linq — Zohar Peled, Dec 21 '21 at 16:09
Meanwhile, `OnChipDayEnumClose` doesn't need to be async. It serves no purpose. — madreflection, Dec 21 '21 at 16:10
What happened to Tuesday and Thursday :) Also if you don't know, there's already a [DayOfWeek](https://learn.microsoft.com/en-us/dotnet/api/system.dayofweek?view=net-6.0) enum. — Trevor, Dec 21 '21 at 16:13
Do you have a List of the filtered options? Use the Except Method to get the filtered List — demoncrate, Dec 21 '21 at 16:17
@zaggler I used Days as an enum easy to convey the problem i am facing . The real enum is a different one Thank you — Sebastian, Dec 21 '21 at 16:18
@ZoharPeled Thank you managed to sort it using Remove method of List — Sebastian, Dec 21 '21 at 16:19
@Sebastian I wouldn't have thought that considering your comment in your post, `my Enum looks like below`... thanks. — Trevor, Dec 21 '21 at 16:19
Does this answer your question? [Filtering collections in C#](https://stackoverflow.com/questions/26196/filtering-collections-in-c-sharp) includes `linq`, `RemoveAll`, `yield` etc. solutions.... — Trevor, Dec 21 '21 at 16:21
I might be being a bit thick, but why is this not just `Remove(Saturday)`? — Caius Jard, Dec 21 '21 at 16:46
`OnChipDayEnumClose` is declared to return a `Task` but it does not in fact return a `Task`... — Dialecticus, Dec 21 '21 at 16:59

Serge · Answer 1 · 2021-12-21T16:40:08.500

You have to re-assign filtered collection after filtering, try this, it was tested in VS and working properly


List<OrderDay> dayChoices = new List<OrderDay> { OrderDay.Wednesday, OrderDay.Friday, OrderDay.Saturday };

dayChoices = OnChipDayEnumClose(dayChoices, OrderDay.Wednesday);


private List<OrderDay> OnChipDayEnumClose(List<OrderDay> dayChoices, OrderDay val)
{
    return dayChoices.Where(s => s != val).ToList();
}

or an alternative variant, thanks to @zaggler

private void OnChipDayEnumClose(List<OrderDay> dayChoices, OrderDay val)
{
    dayChoices.RemoveAll(s => s == val);
}

Remove an Item from C# Enum List

1 Answers1