return list, if empty AND count == 0. jump to else

Question

So I have a list of orders...and if the list is empty I want to to jump to the 'else.'

But because its a list (even if its empty) there still is an instance of it? right? anyway if there are no orders it still goes into the if statement so I tried adding .count == 0...

but it still goes into the if statement...what do I need to say where if there are no actual records in orders go to 'else....thanks for any replies

IEnumerable<OrderRecord> orders = _orderService.GetOrdersByCustomer(id, OrderStatus.Completed).ToArray();

if (orders != null && orders.Count() == 0 )
{
  //order exists
}
else
{
    //no order
}

Don't check for null. It's guaranteed not to be null – Kyle Jul 18 '13 at 14:38 — Kyle, Jul 18 '13 at 14:38

score 11 · Accepted Answer · answered Jul 18 '13 at 14:31

11

You want to check if there are more than 0 items in the list

if (orders != null && orders.Count() > 0 )
{
    //order exists
}
else
{
    //no order
}

The list itself doesn't count as an item.

Or, as suggested by Richard Ev in the comments, you can use orders.Any which will return true if there are elements in the list.

answered Jul 18 '13 at 14:31

keyboardP

68,824
13
156
205

3

Instead of `orders.Count() > 0`, consider using `orders.Any()`. `Any` has the benefit that it does not enumerate the entire collection, which can have a performance impact (if there is a large cost associated with creating an order). It is also arguably more "intentional". Also, it's less to type! :) – Richard Ev Jul 18 '13 at 14:32
@RichardEv - The flip side would be to simply use the `Count`/`Length` property, as it wouldn't invoke the enumerator at all (if performance was important). Having said that, I think `Any` is not only neater but also has a clear intention for anyone reading. – keyboardP Jul 18 '13 at 14:37
good point, I just scrolled right and spotted the `ToArray()` call in the code! – Richard Ev Jul 18 '13 at 14:38
@RichardEv: Even if it's better to use `Any` for readability, `Enumerable.Count` checks if the input sequence is a collection(like array or list), then it uses the `Count` property, `orders` is an array. – Tim Schmelter Jul 18 '13 at 14:56

score 4 · Answer 2 · edited May 23 '17 at 11:45

4

You need to change your condition

orders.Count() == 0

To

orders.Count() > 0

since currently its check if the list contains no record.

You can also try Enumerable.Any like:

if(orders != null && order.Any())

See why its better to use Any in place of Count()

edited May 23 '17 at 11:45

Community

1
1

answered Jul 18 '13 at 14:33

Habib

219,104
29
407
436

1

Even if it's better to use `Any` for readability, `Enumerable.Count` checks if the input sequence is a collection(like array or list), then it uses the `Count` property, `orders` is an array. – Tim Schmelter Jul 18 '13 at 14:55
@TimSchmelter, I agree, didn't see the `ToArray` part just concentrated on `So I have a list of orders` :) – Habib Jul 18 '13 at 14:57

score 3 · Answer 3 · answered Jul 18 '13 at 14:32

3

I assume you want to check for > 0 instead

if (orders != null && orders.Count() > 0 )
{
  //order exists
}

or orders.Any()

answered Jul 18 '13 at 14:32

Tim Schmelter

450,073
74
686
939

return list, if empty AND count == 0. jump to else

3 Answers3