DeSerialize NaN values into JSON using System.Text.Json.Serialization

Question

I Need to convert NaN in Json(as it is not JSON) to Double using using System.Text.Json.Serialization;. For example, I am having following JSON: { "Amount": NaN }

Gajendra Jangid · Answer

To serialized/deserialized, You can use an alternative way (such as strings) Json.NET stores these as strings in the payload then automatically converts to float. To demonstrate you can check the following code: public class ClassWithNumbers { public int IntNumber { get ; set ; } public float FloatNumber { get ; set ; } } // Json Serialization Options to allow literals var options = new JsonSerializerOptions { NumberHandling = JsonNumberHandling.AllowNamedFloatingPointLiterals }; // Json Exmple string json = @ "{" "IntNumber" ":1," "FloatNumber" ":" "NaN" "}" ; ClassWithNumbers obj = System.Text.Json.JsonSerializer.Deserialize (json, options); Output: // obj.IntNumber: 1 // obj.FloatNumber: NaN

Manikandan M · Answer

Hi David, Hope below details will help you to resolve your question. var settings = new JsonSerializerSettings(); var floatConverter = new LawAbidingFloatConverter(); settings.Converters.Add(floatConverter); var myConverter = new JsonNetSerializer(settings); public class LawAbidingFloatConverter : JsonConverter { public override bool CanRead { get { return false; } } public override bool CanWrite { get { return true; } } public override void WriteJson(JsonWriter writer, object value, JsonSerializer serializer) { var val = value as double? ?? (double?)(value as float?); if (val == null || Double.IsNaN((double)val) || Double.IsInfinity((double)val)) { writer.WriteNull(); return; } writer.WriteValue((double)val); } public override object ReadJson(JsonReader reader, Type objectType, object existingValue, JsonSerializer serializer) { throw new NotImplementedException(); } public override bool CanConvert(Type objectType) { return objectType == typeof(double) || objectType == typeof(float); } } Ref Link: https://stackoverflow.com/questions/7814247/serialize-nan-values-into-json-as-nulls-in-json-net

Muhammad Imran Ansari · Answer

The only way these can be successfully serialized/deserialized is by representing them by using an alternative format (such as strings). JSon.NET stores these as strings in the payload then automatically converts to float. public class ClassWithNumbers { public int IntNumber { get; set; } public float FloatNumber { get; set; } } var options = new JsonSerializerOptions { NumberHandling = JsonNumberHandling.AllowNamedFloatingPointLiterals }; string json = @"{""IntNumber"":1,""FloatNumber"":""NaN""}"; ClassWithNumbers obj = System.Text.Json.JsonSerializer.Deserialize (json, options); // obj.IntNumber: 1 // obj.FloatNumber: NaN Pre-Requisite: dll: System.Text.Json; Nuget Package: System.Text.Json;