FirstOrDefault: Default value other than null

Question

As I understand it, in Linq the method FirstOrDefault() can return a Default value of something other than null. What I haven\'t worked out is wha

Answer 1

I just had a similar situation and was looking for a solution that allows me to return an alternative default value without taking care of it at the caller side every time I need it. What we usually do in case Linq does not support what we want, is to write a new extension that takes care of it. That´s what I did. Here is what I came up with (not tested though):

public static class EnumerableExtensions
{
    public static T FirstOrDefault(this IEnumerable items, T defaultValue)
    {
        foreach (var item in items)
        {
            return item;
        }
        return defaultValue;
    }

    public static T FirstOrDefault(this IEnumerable items, Func predicate, T defaultValue)
    {
        return items.Where(predicate).FirstOrDefault(defaultValue);
    }

    public static T LastOrDefault(this IEnumerable items, T defaultValue)
    {
        return items.Reverse().FirstOrDefault(defaultValue);
    }

    public static T LastOrDefault(this IEnumerable items, Func predicate, T defaultValue)
    {
        return items.Where(predicate).LastOrDefault(defaultValue);
    }
}