Convert C# Class to JSON with Example

In previous article, we mentioned Lambda expression in C# (With Examples) but in this article, I have mentioned how we can convert C# Class into JSON string using console application example, which can be used to .NET or .NET Core.

So, create a new console application using Visual Studio 2019 in .NET Core 3 or above.

Once Visual Studio generates a Console application template, we will need to install 'NewtonSoft.JSON' nuget package, so navigate to Tools -> Nuget Package Manager -> Nuget Package Manager Console, then use the below command

Install-Package Newtonsoft.Json

Once, we have installed above package navigate to Program.cs and use the below C# Code, which has sample Student class with sub-class "Subject" and a sample data is added in "Main" method.

using Newtonsoft.Json;
using System;

public class Student
{
    public string FirstName;
    public string LastName;
    public Subject subject;
}

public class Subject
{
    public string Name { get; set; }
    public string Class { get; set; }
}

namespace CSharpClassToJSON
{
    class Program
    {
        static void Main(string[] args)
        {
            var obj = new Student
            {
                FirstName = "Vikram",
                LastName = "Vaswani",
                subject = new Subject
                {
                   Name= "Science",
                   Class = "X"
                }
            };
            var json = JsonConvert.SerializeObject(obj);
            Console.WriteLine(json);
        }
    }
}

Output:

{"FirstName":"Vikram","LastName":"Vaswani","subject":{"Name":"Science","Class":"X"}}

So, as you can see we were able to convert C# Class data into JSON string.

JSON to C# Class

Now, further if you want to deserialize data and convert JSON into C# Class, then you can add some code more

            var classData = JsonConvert.DeserializeObject<Student>(json);
            Console.WriteLine(classData.FirstName + " " + classData.LastName);

Which will give you output as

Vikram Vaswani

That's it, hope it helps.

For .NET 8+

If you are using .NET or newer version of .NET, you don't need to add Nuget Package.

You can use below code

using System;
using System.Text.Json;

public class Student
{
    public string FirstName { get; set; }
    public string LastName { get; set; }
}

public class Program
{
    public static void Main(string[] args)
    {
        // Create a Student object
        Student person = new Student{ FirstName = "Vikram", LastName = "Vaswani" };

        // Serialize the object to a JSON string
        string jsonString = JsonSerializer.Serialize(person);

        // Print the JSON string
        Console.WriteLine(jsonString);
    }
}

In above code, we are using System.Text.Json namespace, which is available by default in .NET Core now, so you can use it directly to convert C# class data into JSON.

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