C# JSON; Deserialize array that sometimes has an empty value (not null)

Question

I'm trying to deserialize a JSON response and I want a function that detects if the array is empty and if it is not empty I want it to return the values.

The JSON array looks like this when empty:

{"metrics":[]}

And when it is not empty it can look like any of the below:

{"metrics":["flow"]}

{"metrics":["energy"]}

{"metrics":["flow","energy"]}

How can I detect this?

It does not work with NullValueHandling since if the array is empty it is not null, it doesn't have any values at all.

I jus get an error about index is not found.

I am returning the array as a List in my classes.

You say you got an error with your code. Can you post the relevant code? — gunr2171
– gunr2171, Commented Oct 12, 2017 at 18:49
Deserialize it the same way each time, then just check if your List is empty or not afterwards — Jonesopolis
– Jonesopolis, Commented Oct 12, 2017 at 18:50
I would think that the JSON deserializer from NewtonSoft would handle this just fine. It would give you an array with length 0. — Kevin Hirst
– Kevin Hirst, Commented Oct 12, 2017 at 18:50

gunr2171 · Accepted Answer · 2017-10-12 18:52:11Z

3

Assuming you're using Newtonsoft.Json for deserializing the json:

class Data
{
    public List<string> Metrics { get; set; }
}

var json = "{\"metrics\":[]}";
var obj = JsonConvert.DeserializeObject<Data>(json);

obj.Metrics will be an empty collection, not null.

Plus, even if it was, you could access it like

var metrics = obj.Metrics ?? new List<string>();

answered Oct 12, 2017 at 18:52

gunr2171

17.7k26 gold badges68 silver badges102 bronze badges

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

Collectives™ on Stack Overflow

C# JSON; Deserialize array that sometimes has an empty value (not null)

1 Answer 1

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

Comments

Your Answer

Sign up or log in

Post as a guest

Related