How to Read and Parse JSON Data From a File in .NET Core

Data is the driving force behind almost every application or service in today’s digital age. As a developer, you may need to work with different types of data, such as JSON data and know that how to read and parse JSON data 1from a file in .NET core. JSON (JavaScript Object Notation) is a lightweight data format that is easy to read and write for both humans and machines. Modern web applications and services frequently use it for data exchange and storage.

If you are working with .NET Core, you may come across scenarios where you need to read and parse JSON data from a file. Fortunately, .NET Core supports JSON serialization and deserialization, making it easy to work with JSON data in your applications.

In this blog, we will guide you on how to read and parse JSON data from a file in .NET Core. We will cover everything from setting up your project to reading and parsing JSON data using the JSON package. By the end of this tutorial, you will have a solid understanding of how to work with JSON data in .NET Core and be able to apply this knowledge to your own projects. So, let’s get started!

Newtonsoft.Json is a popular and widely-used library for working with JSON data in .NET applications. It provides a comprehensive set of features to read, write, and manipulate JSON data, and it’s easy to use.

In this post, we will show you how to read and parse JSON data from a file using Newtonsoft.Json in .Net.

If you are working on an ASP.NET Core project prior to .NET Core 3.0, JSON.NET is likely to be already installed. However, if you are working on a Console Application or a Class Library, you will need to install it by executing the following command in your package manager console.

Before we start, we need to install Newtonsoft.Json. You can either download it from the Newtonsoft website or install it using NuGet Package Manager.

Let’s create a sample JSON file with the following data:

{
  "firstName": "John",
  "lastName": "Doe",
  "age": 25,
  "address": {
    "streetAddress": "123 Main St.",
    "city": "New York",
    "state": "NY",
    "postalCode": "10001"
  },
  "phoneNumbers": [
    {
      "type": "home",
      "number": "212-555-1234"
    },
    {
      "type": "fax",
      "number": "646-555-4567"
    }
  ]
}

To read the above JSON data from a file named “person.json”, we need to do the following:

string jsonData = File.ReadAllText("person.json");

In the above code, we are using the File.ReadAllText() method to read the entire JSON data from the file into a string variable named jsonData.

Now that we have the JSON data in a string variable, we can use the JsonConvert.DeserializeObject() method to parse it into an object.

Person person = JsonConvert.DeserializeObject<Person>(jsonData);

In the above code, we are using the JsonConvert.DeserializeObject() method to parse the JSON data into an object of type Person. The Person class should have properties matching the keys in the JSON data.

For example, if the Person class is defined as follows:

public class Person
{
    public string FirstName { get; set; }
    public string LastName { get; set; }
    public int Age { get; set; }
    public Address Address { get; set; }
    public List<PhoneNumber> PhoneNumbers { get; set; }
}

public class Address
{
    public string StreetAddress { get; set; }
    public string City { get; set; }
    public string State { get; set; }
    public string PostalCode { get; set; }
}

public class PhoneNumber
{
    public string Type { get; set; }
    public string Number { get; set; }
}

Then the JsonConvert.DeserializeObject() method will create an instance of the Person class and populate its properties with the values from the JSON data.

In this post, we have shown you how to read and parse JSON data from a file using Newtonsoft.Json in C#. With Newtonsoft.Json, it’s easy to work with JSON data in your .NET applications. We hope this tutorial helps you get started with working with JSON data in your .NET applications.