Question

I have the following code

class MyJSONSerializableClass
{        
    [JsonProperty("index")]
    public int Index { get; set; };

    [JsonIgnore]
    public long Id { get; set; };
}

var collection = new List<MyJSONSerializableClass>()
{
    new MyJSONSerializableClass() 
    {
        Index = 10,
        Id = 1000
    }
};

string jsonOutput = JsonConvert.SerializeObject(collection);

jsonOutput would be

[{ index: 10 }]

I would like jsonOutput to be

[ 10 ]

Is there any class attribute I can apply to MyJSONSerializableClass that would tell JSON.NET to emit only the property Index, instead of the entire object?

Something along the lines of

[JsonOutput(f => f.Index)]
class MyJSONSerializableClass
{
   ...
}

Thanks

Answer 1

Not sure about the attributes, but alternatively, you could try

JsonConvert.SerializeObject(collection.Select(o => o.Index)).

As per documentation, all IEnumerable’s will be arrays.