How to turn an object into a JSON string in C#

Richard C.
—The Problem
In C# you often need to convert a complex object to JSON to print it to the screen for debugging, or to send over the network to another application. So how do we convert an object like the following to a JSON string?
class Person { public string Name; public DateTime Birth; public Address Address; } class Address { public string Road; public string Suburb; }
The Solution
Writing JSON is easy in .NET:
- Import:
using System.Text.Json; - Convert your object to a string:
var json = JsonSerializer.Serialize(alice);
The converter will work only on public properties with getters and setters though. So we have to convert our fields in the introduction to properties:
using System; using System.Text.Json; class Person { public string Name { get; set; } public DateTime Birth { get; set; } public Address Address { get; set; } } class Address { public string Road { get; set; } public string Suburb { get; set; } } public class Program { public static void Main() { var alice = new Person() { Name = "Alice", Birth = new DateTime(2000, 01, 01), Address = new Address() { Road = "oak", Suburb = "sunnydale" } }; var json = JsonSerializer.Serialize(alice); Console.WriteLine(json); // prints {"Name":"Alice","Birth":"2000-01-01T00:00:00","Address":{"Road":"oak","Suburb":"sunnydale"}} } }
Deserialize JSON Back to an Object
To convert a JSON string back to an object, run deserialize, specifying the class you want to convert the string to:
var alice2 = JsonSerializer.Deserialize<Person>(json);
You need to surround this code in a try-catch block to handle JSON that does not meet your class definition.
Settings
To configure custom JSON conversion settings, like handling trailing commas, comments, and null values, view the Microsoft documentation here.
You can convert with settings like this:
var settings = new JsonSerializerOptions() {AllowTrailingCommas = true}; var json = JsonSerializer.Serialize(alice, settings);
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