Getting specific key values | JSON | C#

Question

How do I manage to filter after specific key values in a json file? I am using C#. I want to get every distance.value and save them into an array of doubles. That way I want to create a distance matrix.

Stackoverflow wants me to add more information but I am not sure what additional code snippets are useful. If I am missing something I will add it to the comments.

Here is the json output.

{
   "destination_addresses" : [],
   "origin_addresses" : [],
   "rows" : [
      {
         "elements" : [
            {
               "distance" : {
                  "text" : "1 m",
                  "value" : 0
               },
               "duration" : {
                  "text" : "1 Minute",
                  "value" : 0
               },
               "status" : "OK"
            },
            {
               "distance" : {
                  "text" : "5 m",
                  "value" : 5
               },
               "duration" : {
                  "text" : "1 Minute",
                  "value" : 1
               },
               "status" : "OK"
            },
            {
               "distance" : {
                  "text" : "3,7 km",
                  "value" : 3730
               },
               "duration" : {
                  "text" : "10 Minuten",
                  "value" : 582
               },
               "status" : "OK"
            }
         ]
      },
      {
         "elements" : [
            {
               "distance" : {
                  "text" : "0,5 km",
                  "value" : 510
               },
               "duration" : {
                  "text" : "3 Minuten",
                  "value" : 182
               },
               "status" : "OK"
            },
            {
               "distance" : {
                  "text" : "1 m",
                  "value" : 0
               },
               "duration" : {
                  "text" : "1 Minute",
                  "value" : 0
               },
               "status" : "OK"
            },
            {
               "distance" : {
                  "text" : "3,7 km",
                  "value" : 3725
               },
               "duration" : {
                  "text" : "10 Minuten",
                  "value" : 581
               },
               "status" : "OK"
            }
         ]
      }    
   ],
   "status" : "OK"
}

Have you tried anything yet? Maybe you already looped over the file entries to get the values? — Björn Heiß
– Björn Heiß, Commented Oct 9, 2020 at 13:20

Sergey Nazarov · Accepted Answer · 2020-10-08 21:19:38Z

1

var json = "_YOUR_JSON_";
var jobject = JObject.Parse(json);
var doubles = jobject.SelectTokens("$.rows[*].elements[*].distance.value")
    .Values<double>()
    .ToArray();

Notes:

The query string rows[*] contains the JSONPath wildcard operator [*]. This operator matches all array elements under the parent element "rows".
Same as previous for elements[*]
distance.value - path to required value
As long as SelectTokens returns IEnumerable<JToken> we need to cast our values to double, so call Values<double>()
Finally cast our IEnumerable<double> to array.

answered Oct 8, 2020 at 21:19

Sergey Nazarov

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3 Comments

PabloS Over a year ago

Thanks alot!! My double looks like this: var result = new double[numStops, numStops]; How can I convert it to an two dimensional array.?

Sergey Nazarov Over a year ago

You want an two dimensional array with same values?

PabloS Over a year ago

Yeh similiar to a distance matrix. for (int j = 0; j < (numStops*numStops);){ for (int i = 0; i < numStops; i++){ for (int h = 0; h < numStops; h++){ result[i,h] = arr[j]; j++; } } }

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