Does C# have IsNullOrEmpty for List/IEnumerable?

Question

I know generally empty List is more prefer than NULL. But I am going to return NULL, for mainly two reasons

1. I have to check and handle null values explicitly,

Answer 1

nothing baked into the framework, but it's a pretty straight forward extension method.

See here

/// 

    /// Determines whether the collection is null or contains no elements.
    /// 
    /// The IEnumerable type.
    /// The enumerable, which may be null or empty.
    /// 
    ///     true if the IEnumerable is null or empty; otherwise, false.
    /// 
    public static bool IsNullOrEmpty(this IEnumerable enumerable)
    {
        if (enumerable == null)
        {
            return true;
        }
        /* If this is a list, use the Count property for efficiency. 
         * The Count property is O(1) while IEnumerable.Count() is O(N). */
        var collection = enumerable as ICollection;
        if (collection != null)
        {
            return collection.Count < 1;
        }
        return !enumerable.Any(); 
    }

Daniel Vaughan takes the extra step of casting to ICollection (where possible) for performance reasons. Something I would not have thought to do.