JSON Processing with System.Text.Json

using System;
using System.Text.Json;

// A plain class (a DTO — "data transfer object") that mirrors your JSON shape.
class Book
{
    public string Title { get; set; } = "";
    public string Author { get; set; } = "";
    public int Year { get; set; }
    public bool InStock { get; set; }
}

class Program
{
    static void Main()
    {
        // 1) Build a normal C# object.
        var book = new Book
        {
            Title = "The Pragmatic Programmer",
            Author = "Hunt & Thom
...

using System;
using System.Text.Json;

class Movie
{
    public string Title { get; set; } = "";
    public int Year { get; set; }
}

class Program
{
    static void Main()
    {
        // 🎯 YOUR TURN — replace each ___ then press "Try it Yourself".

        // 1) Build a Movie object.
        var movie = new Movie { Title = "Inception", Year = 2010 };

        // 2) Make options that pretty-print the JSON.
        var options = new JsonSerializerOptions
        {
            WriteIndented = _
...

using System;
using System.Text.Json;

class Weather
{
    // System.Text.Json needs a PUBLIC parameterless constructor (the
    // default one you get for free) so it can build the object, then
    // fill these settable properties one by one.
    public string City { get; set; } = "";
    public double TempC { get; set; }
    public bool IsRaining { get; set; }
}

class Program
{
    static void Main()
    {
        // The JSON you might receive from a weather API.
        string json = "{\"ci
...

using System;
using System.Text.Json;

class User
{
    public string Name { get; set; } = "";
    public int Age { get; set; }
}

class Program
{
    static void Main()
    {
        // 🎯 YOUR TURN — replace each ___ then press "Try it Yourself".

        string json = "{\"name\":\"Ada\",\"age\":36}";

        // 1) Deserialize the JSON into a User.
        //    The type goes in the angle brackets:  Deserialize<User>(...)
        User? user = JsonSerializer.Deserialize<___>(json);  // 👉 the 
...

using System;
using System.Text.Json;
using System.Text.Json.Serialization;

// Real APIs love snake_case keys ("first_name") that aren't valid C#
// identifiers. [JsonPropertyName] maps the exact JSON key to a tidy
// C# property name — both directions, serialize AND deserialize.
class Account
{
    [JsonPropertyName("first_name")]
    public string FirstName { get; set; } = "";

    [JsonPropertyName("last_name")]
    public string LastName { get; set; } = "";

    // [JsonIgnore] leaves this 
...

using System;
using System.Text.Json;
using System.Text.Json.Nodes;

class Program
{
    static void Main()
    {
        string json = """
        {
            "name": "Repo",
            "stars": 1280,
            "tags": ["csharp", "json", "dotnet"]
        }
        """;

        // === JsonDocument — read-only, very low allocation ===
        // Great when you only need to PEEK at a few values and won't
        // change anything. 'using' disposes its pooled memory afterwards.
        usin
...