Json Dll: Newtonsoft

string json = @" 'store': 'book': [ 'title': 'The Hobbit' ] "; JObject obj = JObject.Parse(json); string title = obj["store"]["book"][0]["title"].ToString(); obj["store"]["book"][0]["price"] = 12.99; // Modify in place One of the most painful serialization problems is preserving derived types. Newtonsoft solves this with TypeNameHandling . By adding a "$type" property to the JSON, it can deserialize an interface or abstract class back into the correct concrete type.

var settings = new JsonSerializerSettings newtonsoft json dll

NullValueHandling = NullValueHandling.Ignore, ContractResolver = new DefaultContractResolver NamingStrategy = new SnakeCaseNamingStrategy() , Formatting = Formatting.Indented ; string json = JsonConvert.SerializeObject(myObject, settings); Need to serialize a DateTime as a Unix timestamp? Map an enum to a string instead of an int? Handle a polymorphic type hierarchy where the base class doesn’t know its children? JsonConverter is your answer. string json = @" 'store': 'book': [ 'title':

public override void WriteJson(JsonWriter writer, DateTime value, JsonSerializer serializer) => writer.WriteValue((value - new DateTime(1970, 1, 1)).TotalSeconds); public override DateTime ReadJson(JsonReader reader, Type objectType, DateTime existingValue, bool hasExistingValue, JsonSerializer serializer) => new DateTime(1970, 1, 1).AddSeconds(Convert.ToDouble(reader.Value)); You don't always have a strongly-typed class. Sometimes you need to parse, query, or modify JSON on the fly. Newtonsoft’s JObject lets you treat JSON like an XML DOM. JsonConverter is your answer

Migration tools like System.Text.Json 's source generator can help, but many teams have simply decided: if it ain't broke, don't fix it. Newtonsoft.Json has had its share of CVEs. Most stem from using TypeNameHandling on untrusted input—a classic deserialization vulnerability that can lead to remote code execution.

public class UnixDateTimeConverter : JsonConverter<DateTime>

TypeNameHandling = TypeNameHandling.Auto ; (Warning: Only use this for trusted data—it's a security risk if you deserialize untrusted JSON.) Newtonsoft.Json is not the fastest library anymore. Microsoft's System.Text.Json is significantly faster, allocates less memory, and is more modern (using Utf8JsonReader and Utf8JsonWriter ). Benchmarks typically show System.Text.Json being 20-50% faster for serialization and 30-80% faster for deserialization.