JSON & C#

1.System.Text.Json.Utf8JsonReader
ref: https://docs.microsoft.com/en-us/dotnet/core/whats-new/dotnet-core-3-0
 https://github.com/ysharplanguage/FastJsonParser#Overview

2. Newtonsoft.Json library

 using NewTonsoft.Json; //Using Manage NuGet Packages installs Newtonsoft.Json.
 Cat cat2 = new Cat(){name="hik",age=3};
 string s1=Newtonsoft.Json.JsonConvert.SerializeObject(cat2);
  Cat   cat3 = JsonConvert.DeserializeObject<Cat>(JSONstr);


  string outStr2 = JsonConvert.SerializeObject(cat2);


private string CapitalFirstLetter(string s)
 {
            try
            {
                string rs = char.ToUpper(s[0]) + s.Substring(1);
                return rs;
            }catch(Exception e) { return s; }
 }
3.JavaScriptSerializer

  using System.Web.Script.Serialization;
  using System.IO;
 //Script.Serialization is in System.Web.Extensions.
 //We need to add a reference that is System.Web.Extensions in Assemblies in Reference Manager
 string JSONstr= File.ReadAllText("JSON.json");
// $"{{\"name\":\"{name1}\",\"age\":1}}"
 JavaScriptSerializer ser = new JavaScriptSerializer();
 Cat   cat1 = ser.Deserialize<Cat>(JSONstr);
 Cat cat2 = new Cat(){name="hik",age=3};
 string outStr = ser.Serialize(cat2);
 File.WriteAllText("Cat.json",outStr);

4 .simdjson : Parsing gigabytes of JSON per second
https://github.com/lemire/simdjson