Study of System.Text.Json

global.json

{
    "sdk": {
        "version": "3.1.300",
        "rollForward": "latestPatch"
    }
}

Person.cs

namespace StudyOfSystemTextJson
{
    public class Person
    {
        public string Name { get; }

        public int Age { get; }

        public Person(string name, int age)
        {
            Name = name;
            Age = age;
        }

        public override string ToString() => $"{Name}, {Age}";
    }
}

Program.cs

using System;
using System.Text.Json;

namespace StudyOfSystemTextJson
{
    class Program
    {
        static void Main(string[] args)
        {
            var person = new Person(
                name: "Taro",
                age: 23
            );

            var jsonText = JsonSerializer.Serialize(person);
            Console.WriteLine(jsonText);

            var newPerson = JsonSerializer.Deserialize<Person>(jsonText);
            Console.WriteLine(newPerson.ToString());
        }
    }
}

StudyOfSystemTextJson.csproj

<Project Sdk="Microsoft.NET.Sdk">

  <PropertyGroup>
    <OutputType>Exe</OutputType>
    <TargetFramework>netcoreapp3.1</TargetFramework>
    <LangVersion>8.0</LangVersion>
  </PropertyGroup>

  <ItemGroup>
    <PackageReference Include="System.Text.Json" Version="5.0.0-preview.7.20364.11" />
  </ItemGroup>

</Project>