how to get from array in json array

Question

I am trying to parse {"type_history":[["15","0.07","apple"],["13","0.03","banana"],["10","0.23","lemon"]]},I try to get array in JsonArray but fail.

String myJson="{"type_history":[["15","0.07","apple"],["13","0.03","banana"],["10","0.23","lemon"]]}";
ArrayList<UserType> rtn = new ArrayList<>();
JSONArray j=myJson.optJSONArray("type_history");
for (int i = 0; i < j.length(); i++) {
    UserType tmp = new UserType();
    JSONArray tmpArray = new JSONArray(Arrays.asList(j.get(i)));
    tmp.setType(tmpArray.getString(0));
    tmp.setValue(Float.parseFloat(tmpArray.getString(1)));
    rtn.add(tmp);
}

in tmpArray.getString(0), I still get ["15","0.07","apple"],not get "15" how to fix my code for get value from this array?

letsCode · Accepted Answer · 2019-06-26 19:31:07Z

You have a JSONArray of JSONArrays.... so, lets say you want to get 15... you would do something like...

JSONObject o2 = new JSONObject(myJson);
JSONArray arr = o2.getJSONArray("type_history");
System.out.println(arr.getJSONArray(0).get(0));

Lets say you want to get all of the first elements in each.. you would do...

for (int i = 0; i < arr.length(); i++) {
    System.out.println(arr.getJSONArray(i).get(0));
}

Let's dig more....

If you want to print everything...

    for (int i = 0; i < arr.length(); i++) {
        for (int j = 0; j < arr.getJSONArray(i).length(); j++) {
            System.out.println(arr.getJSONArray(i).get(j));
        }
        System.out.println("----------");
    }

That will print:

15
0.07
apple
----------
13
0.03
banana
----------
10
0.23
lemon
----------

I think your data structure should change tho. Its not very informative of what everything is. What does the 15, .07 mean from the apple? Maybe do a JSONArray of JSONObjects... would be a lot cleaner and easier to parse

You want to do whatever it takes to get away from hard coding indexes... (getJSONArray(0))

Bosco · Accepted Answer · 2019-06-26 21:01:28Z

0

Here we go:

var listStr: JSONArray? = null

val json = "{type_history:[[15,0.07,apple],[13,0.03,banana],[10,0.23,lemon]]}"
val jsonObject = JSONObject(json)

val jsonArray = jsonObject.getJSONArray("type_history")

for(i in 0 until jsonArray.length()){
    listStr = jsonArray.get(i) as JSONArray
    for(x in 0 until listStr.length()) {
        Log.d("mlogs", listStr.get(x).toString())
    }
}

edited Jun 26, 2019 at 21:01

Bosco

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answered Jun 26, 2019 at 20:09

Edhar Khimich

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