CODEWITHSUNDEEP
javaandroidjsonapiandroid-volley
astric mobiles
astric mobiles

Reputation: 476

Why is my code returning value of 'null' from a nested JSON array

So I'm trying to get the 'statusSeveretyDescription' which is inside 'lineStatus'. The first 'for' loop works, however, the nested loop returns null.. A pointer in the right direction would be much appreciated. Please see code and an image of the JSON below.

JSONArray array = new JSONArray(response);
for (int i = 0; i < array.length(); i++) {

    JSONObject object = array.optJSONObject(i);
    String line = object.optString("id");

    //nested array
    JSONArray arrayStatus = object.getJSONArray("lineStatuses");
    int len = arrayStatus.length();

    for (int j = 0; j < len; j++) {                                
        JSONObject o = arrayStatus.getJSONObject(j);
        String statusSeverityDescription = o.optString(
                                            "statusSeverityDescription", "");
    }

    if (line != null) {
        tubeLines.add(line  + statusSeverityDescription);
    }

    // Once we added the string to the array, we notify the arrayAdapter
    arrayAdapter.notifyDataSetChanged();
}

enter image description here

Upvotes: 1

Views: 432

Answers (1)

soote
soote

Reputation: 3260

You have 2 issues.

1) Your variable scoping is incorrect, your statusSeverityDescription variable is being deallocated as soon as the for loop ends. To fix this, move String statusSeverityDescription outside of the for loop, like so

String statusSeverityDescription;
for (int j = 0; j < len; j++) {                                
   JSONObject o = arrayStatus.getJSONObject(j);
   statusSeverityDescription = o.optString(
                                        "statusSeverityDescription", "");
}

2) statusSeverityDescription should be an array which store all the statusSeverityDescription's in your json payload. So make it an array, or understand that the last processed statusSeverityDescription for a given lineStatuses will be the statusSeverityDescription you're left with.

Upvotes: 2

Related Questions