JSON Round Trip in C# - Example You Can Run Online

Introduction

A round trip is a practical way to verify a model's JSON representation.

System.Text.Json uses public constructor parameters and properties to reconstruct the record.

Runnable C# example

C#

Program.cs

using System;
using System.Text.Json;
record Settings(string Theme, int FontSize);
class Program
{
    static void Main()
    {
        string json = JsonSerializer.Serialize(new Settings("dark", 16));
        Settings? settings = JsonSerializer.Deserialize<Settings>(json);
        Console.WriteLine($"{settings?.Theme}: {settings?.FontSize}");
    }
}

Result of running the code

dark: 16

Practice with the debugger

Set a breakpoint on an important assignment or condition, click Debug, and inspect the local values before stepping to the next line.

Practice with a challenge

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