Question 198668 in Json Question posted in
Our archive of expertly curated questions and answers provides insights and solutions to common problems related to this popular data interchange format. From parsing and manipulating JSON data to integrating it with various programming languages and web services, our archive has got you covered. Start exploring today and take your JSON skills to the next level

Json – How do I iterate over "Items" and extract properties and values (VB Net/c#)

I would like to iterate over the items in the json shown below. Not every item has all the same fields/key values.
The items I want to iterate over are found at "items":

How do I iterate over these items?
I can get the items into an array called Items:
Dim ParseJson As JObject = JObject.Parse(APIReturn)
Dim Items = ParseJson.SelectToken("items").ToString()

How can I iterate over this array, and extract the values from each item?

As I get each item, I want to extract the "title", "date", and "category". How do get these values from the json?

{
    "title": "Massapequa Park July 2023",
    "date": "2023-07-01T20:52:43.581Z",
    "location": {
        "title": "Massapequa Park, New York, USA",
        "city": "Massapequa Park",
        "tzid": "America/New_York",
        "latitude": 40.68038,
        "longitude": -73.45512,
        "cc": "US",
        "country": "United States",
        "admin1": "New York",
        "asciiname": "Massapequa Park",
        "geo": "geoname",
        "geonameid": 5126187
    },
    "range": {
        "start": "2023-07-01",
        "end": "2023-07-08"
    },
    "items": [
        {
            "title": "Holiday 1",
            "date": "2023-07-01",
            "hdate": "H1",
            "category": "Holiday ",
        },
        {
            "title": "Meeting: 9:19pm",
            "date": "2023-07-01T21:19:00-04:00",
            "category": "Meeting",
            "title_orig": "Meeting",
        },
        {
            "title": "MiniFast begins",
            "date": "2023-07-06T03:42:00-04:00",
            "category": "fast",
            "subcat": "mini fast",
            "memo": "short fast"
        },
        {
            "title": "Stop Mini Fast",
            "date": "2023-07-06",
            "hdate": "Hold 1",
            "category": "fast",
            "subcat": "mini fast",
            "memo": "short fast"
        },
        {
            "title": "Fast ends",
            "date": "2023-07-06T21:08:00-04:00",
            "category": "Light",
            "subcat": "fast",
            "memo": "Old Shirt"
        },
        {
            "title": "18 Before Dusk: 8:09pm",
            "date": "2023-07-07T20:09:00-04:00",
            "category": "Ready Lights",
            "title_orig": "18 Before Dusk",
            "memo": "Nachos"
        },
        {
            "title": "Holiday 7",
            "date": "2023-07-08",
            "hdate": "7th Holiday",
            "category": "Holiday ",
        },
        {
            "title": "Meeting: 9:17pm",
            "date": "2023-07-08T21:17:00-04:00",
            "category": "Meeting",
            "title_orig": "Meeting",
        }
    ]
}
Tags:

2

Answers


  1. 0

    Assuming you’re using Newtonsoft.Json, then it’s simple-enough:

    1. Use JToken.Parse on the response body (APIReturn) and then verify the parsed JToken is an JObject (as it could be a null literal, or a JArray, or something else).
    2. Use JObject.Property("items") to get the JProperty for the "items": property.
    3. Verify that the JProperty.Value is a JArray (as opposed to null or another JObject or something else).
    4. Iterate over the JTokens in that JArray: test each one to verify it’s a JObject (or use Linq’s OfType<JObject>()) and then safely extract the desired values.

    Something like this:

    String jsonText = ... // await File.ReadAllTextAsync( @"2023-07-01-json.txt" );

if( JToken.Parse( jsonText ) is JObject root )
{
    if( root.Property( "items" ) is JProperty p && p.Value is JArray items )
    {
        var extractedItems = items
            .OfType<JObject>()
            .Select( o => (
                title   : o.Property( "title"    )?.Value.ToString(),
                date    : o.Property( "date"     )?.Value.ToString(),
                category: o.Property( "category" )?.Value.ToString()
            ) )
            .ToList();
            
        extractedItems.Dump(); // `Dump` is a LinqPad method
    }
}

    Screenshot proof:

    enter image description here

    (Ignore how LinqPad reports the ValueTuple member names as Item1, Item2, and Item3: C# IntelliSense will let you correctly dereference those members by the names title, date, and category in code).

    Login or Signup to reply.
  2. 0

    you can use this code

    Dim Items As JArray = JObject.Parse(jsonString).SelectToken("items")

Dim result = Items.Select(Function(x)
                           Return New With {Key .Title = x("title").ToString,
                                            Key .Category = x("category").ToString}
                                  End Function).ToList()
    Login or Signup to reply.
Please signup or login to give your own answer.

Back To Top
Search