Is the result of List<T>.FindAll guaranteed to be in the same order as the original list?

Question

If I've got a List with the following entries:

Apple Banana Grape Cherry Orange Kiwi

Is the result of

fruit.FindAll(f => f.Length == 6)

guaranteed to always be

Banana Cherry Orange

or could the order be different?

Answer 1

It's not guaranteed in the sense that it doesn't say it in the documentation, however if you look at how it's currently implemented, then yes, it'll always come back in the same order.

Here's how it's currently implemented:

public List<T> FindAll(Predicate<T> match)
{
    if (match == null)
    {
        ThrowHelper.ThrowArgumentNullException(ExceptionArgument.match);
    }
    List<T> list = new List<T>();
    for (int i = 0; i < this._size; i++)
    {
        if (match(this._items[i]))
        {
            list.Add(this._items[i]);
        }
    }
    return list;
}

As you can see, it's a simple for loop that sequentially goes through the list, and adds the items that match.