Get sub-array from JSON

java, json

Solution

Iteration cannot be avoided here as `org.json` and other Json parsers as well provide random access to objects but not to their properties collectively (as a collection). So, you can't query something like "all name properties of all contact objects" unless you probably get a Json parser like Gson to unmarshall it that way.

But, that's too much to just avoid a `for` loop when you can definitely shorten the parse by making use of the appropriate API methods to avoid unnecessary object casts.

JSONArray contacts = jsonObject.getJSONArray("contact");
String[] contactNames = new String[contacts.length()];
for(int i = 0 ; i < contactNames.length; i++) {
    contactNames[i] = contacts.getJSONObject(i).getString("name");
}

Problem

I parsing some data from a json file. Here is my JSON File. ``` [ { "topic": "Example1", "contact": [ { "ref": [ 1 ], "corresponding": true, "name": "XYZ" }, { "ref": [ 1 ], "name": "ZXY" }, { "ref": [ 1 ], "name": "ABC" }, { "ref": [ 1, 2 ], "name":"BCA" } ] , "type": "Presentation" }, { "topic": "Example2", "contact": [ { "ref": [ 1 ], "corresponding": true, "name": "XYZ" }, { "ref": [ 1 ], "name": "ZXY" }, { "ref": [ 1 ], "name": "ABC" }, { "ref": [ 1, 2 ], "name":"BCA" } ] , "type": "Poster" } ] ``` I can fetch and store data one by one. Like this one ``` JSONArray getContactsArray = new JSONArray(jsonObject.getString("contact")); for(int a =0 ; a < getContactsArray.length(); a++) { JSONObject getJSonObj = (JSONObject)getContactsArray.get(a); String Name = getJSonObj.getString("name"); } ``` 1)Now, my question is there any way to get all `name` values for each array with single query. 2) Can I get all those values in an `Array` ? Please correct me, if I am doing anything wrong. Thank you.

Original source