Question

I have a problem with the following. I have a collection:

Collection<Vehicle> list = new Collection<Vehicle>();

code = 1,2,3, Description = "aaa"
code = 10,438,13, Description = "bbb"
code = 81,8623,362, Description = "ccc"
code = 163,4312,53, Description = "ddd"
...

But I only care about some of them.. The list I care about is here, i.e. codesCareAbout = “1|2|3|163|4312|53”

I need to iterate through the collection and either deleting the Vehicle I don’t care about, or cherry picking into another list containing the Vehicles I care about?

Any suggestions?

Many thanks,
James

Answer 1

You can iterate your list backwards, and use RemoveAt using the for index to remove from the list:

for (int i = list.Count - 1; i >= 0; i--)
{
    Foo item = list[i];

    if (IsFoobar(item))
        list.RemoveAt(i);
}

Counting backwards is required so that you don’t mutate your index counting as you go, using a for loop is required because you cannot mutate a list being enumerated with an enumerator.

Alternatively, do as you suggested, populate into an empty list the stuff you want – however, usage depends on whether you need to modify the list you are given or can make a new list.