Checking if a typed object array is not empty

Question

I have a Item[] _items array of items, where some of the items may be null. I wish to check if the array contains at least one non-null item.

My current implementations seems a little complicated:

    internal bool IsEmtpy { get { return (!(this.NotEmpty)); } }
    private bool IsNotEmpty { get { return ( this.Items.Any(t => t != null));} }

So my question is: Is there a simpler way to check if a typed array of reference objects contains at least one non null object?

Why do you think it's complicated? it seems quite clear and compact to my eyes. Maybe you can put this logic to a custom extension mehod, but the logic itself won't change. — Steve B
– Steve B, Commented Jul 2, 2012 at 8:47
@leppie (and Steve B) I hate the double negation. In my implementation it's empty if it's not not empty :( — Avi
– Avi, Commented Jul 2, 2012 at 8:58
@AdamHouldsworth Thanks. Downvotes are so unhelpful, and are the reason why I quit "programmers"... — Avi
– Avi, Commented Jul 2, 2012 at 8:58

Adam Houldsworth · Accepted Answer · 2012-07-02 09:24:52Z

2

There is no complexity in your implementation. Basically, the only way to check whether there are non-null values in the array is to look through all values until you will reach non-null value or the end of the array.

The following code is easier to understand though:

internal bool IsEmtpy { get { return this.Items.All(t => t == null); } }
private bool IsNotEmpty { get { return this.Items.Any(t => t != null); } }

And it is probably better to extend IEnumerable as follows:

public static class Extensions {

    public static bool ContainsOnlyEmpty<TSource>(this IEnumerable<TSource> source) {
        return source.All(t => t == null);
    }

    public static bool ContainsNonEmpty<TSource>(this IEnumerable<TSource> source) {
        return source.Any(t => t != null);
    }

}

and use it like this: bool nonEmpty = this.Items.ContainsNonEmpty();

edited Jul 2, 2012 at 9:24

Adam Houldsworth

64.8k11 gold badges161 silver badges190 bronze badges

answered Jul 2, 2012 at 8:47

penartur

9,9325 gold badges41 silver badges51 bronze badges

Sign up to request clarification or add additional context in comments.

9 Comments

penartur Over a year ago

@leppie Please, forgive me my terrible English :)

leppie Over a year ago

No problem, I had to look up the meaning too ;p

penartur Over a year ago

@leppie I didn't remember the word exactly, so I even opened the dictionary to look up for it... but then I completely forgot about it and submitted the answer :)

Avi Over a year ago

Thanks - It's the "all" I've been missing, though now that I understand the answer I think the double negation is more efficient because most of my arrays are "mostly full" so the any-not-null will return faster.

Henrik Over a year ago

@Avi - no, there's no performance difference. Both Any and All return as soon as a non-null element is found.

|

Collectives™ on Stack Overflow

Checking if a typed object array is not empty

1 Answer 1

9 Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

9 Comments

Your Answer

Sign up or log in

Post as a guest

Related