Working with JSON – Reading a Data File

With reading a JSON object, you will need to have your JSON data. You can either read in a string, or read a file into a string. Here we have some sample data:

[
  {
    "category": "HISTORY",
    "air_date": "2004-12-31",
    "question": "'For the last 8 years of his life, Galileo was under house arrest for espousing this man's theory'",
    "value": "200",
    "answer": "Copernicus",
    "round": "Jeopardy!",
    "show_number": "4680"
  },
  {
    "category": "ESPN's TOP 10 ALL-TIME ATHLETES",
    "air_date": "2004-12-31",
    "question": "'No. 2: 1912 Olympian; football star at Carlisle Indian School; 6 MLB seasons with the Reds, Giants & Braves'",
    "value": "200",
    "answer": "Jim Thorpe",
    "round": "Jeopardy!",
    "show_number": "4680"
  },
  {
    "category": "EVERYBODY TALKS ABOUT IT...",
    "air_date": "2004-12-31",
    "question": "'The city of Yuma in this state has a record average of 4,055 hours of sunshine each year'",
    "value": "200",
    "answer": "Arizona",
    "round": "Jeopardy!",
    "show_number": "4680"
  },
  {
    "category": "THE COMPANY LINE",
    "air_date": "2004-12-31",
    "question": "'In 1963, live on \"The Art Linkletter Show\", this company served its billionth burger'",
    "value": "200",
    "answer": "McDonald's",
    "round": "Jeopardy!",
    "show_number": "4680"
  }
]

This minor sample came from a much larger file set: https://domohelp.domo.com/hc/en-us/articles/360043931814-Fun-Sample-DataSets

Then we need to have a class which we can use to read in the data.

class JeopardyQuestion
    {
        public string category { get; set; }
        public string airDate { get; set; }
        public string question { get; set; }
        public int value { get; set; }
        public string answer { get; set; }
        public string round { get; set; }
        public int show_number { get; set; }

        public JeopardyQuestion()
        {
        }

        public JeopardyQuestion(string category, string airDate, string question, 
            int value, string answer, string round, int show_number)
        {
            this.category = category;
            this.airDate = airDate;
            this.question = question;
            this.value = value;
            this.answer = answer;
            this.round = round;
            this.show_number = show_number;
        }
    }

This information is fairly simple for this example. We could of course have much more complicated data if necessary.

Note: The JSON deserialize function will want a default (no-arg) constructor.

Now, inside our function where we’re going to read the data, we will load the data:

System.Console.WriteLine("Now to read in the data...");
string json = File.ReadAllText("jeapordy.json");

Note: We will have to import (use) using System.IO; to access File, and System.Text.Json to get the JSON library.

And then load the JSON data.

JeopardyQuestion[] questions = JsonSerializer.Deserialize<JeopardyQuestion[]>(json);

Of course, once you import the data, you should do something with it:

for(int i = 0; i < questions.Length; i++)
{
     Console.WriteLine("Q: " + questions[i].question);
     Console.WriteLine("A: " + questions[i].answer);
     Console.WriteLine();
}

Working with JSON – Reading a Data File was originally found on Access 2 Learn