How do I remove a specific element from a JSONArray?

Question

I am building one app in which I request a PHP file from server. This PHP file returns a JSONArray having JSONObjects as its elements e.g.,

[ 
  {
    "uniqid":"h5Wtd", 
    "name":"Test_1", 
    "address":"tst", 
    "email":"ru_tst@tst.cc", 
    "mobile":"12345",
    "city":"ind"
  },
  {...},
  {...},
  ...
]

my code:

/* jArrayFavFans is the JSONArray i build from string i get from response.
   its giving me correct JSONArray */
JSONArray jArrayFavFans=new JSONArray(serverRespons);
for (int j = 0; j < jArrayFavFans.length(); j++) {
  try {
    if (jArrayFavFans.getJSONObject(j).getString("uniqid").equals(id_fav_remov)) {
      //jArrayFavFans.getJSONObject(j).remove(j); //$ I try this to remove element at the current index... But remove doesn't work here ???? $
      //int index=jArrayFavFans.getInt(j);
      Toast.makeText(getParent(), "Object to remove...!" + id_fav_remov, Toast.LENGTH_SHORT).show();
    }
  } catch (JSONException e) {
    // TODO Auto-generated catch block
    e.printStackTrace();
  }
}

How do I remove a specific element from this JSONArray?

Vinothkumar Arputharaj · Accepted Answer · 2021-05-04T02:08:47.110

Try this code

ArrayList<String> list = new ArrayList<String>();     
JSONArray jsonArray = (JSONArray)jsonObject; 

if (jsonArray != null) { 
   int len = jsonArray.length();
   for (int i=0;i<len;i++){ 
    list.add(jsonArray.get(i).toString());
   } 
}
//Remove the element from arraylist
list.remove(position);
//Recreate JSON Array
JSONArray jsArray = new JSONArray(list);

Edit: Using ArrayList will add "\" to the key and values. So, use JSONArray itself

JSONArray list = new JSONArray();     
JSONArray jsonArray = new JSONArray(jsonstring); 
int len = jsonArray.length();
if (jsonArray != null) { 
   for (int i=0;i<len;i++)
   { 
       //Excluding the item at position
        if (i != position) 
        {
            list.put(jsonArray.get(i));
        }
   } 
}

if (jsonArray != null) makes no sense in your edit sample, because it will never be null. And even if it would, the line before it would throw a NullPointerException. This is also the case in the original sample. — hounce, Dec 15 '20 at 10:21

C-- · Answer 2 · 2015-03-11T18:45:55.290

20

In case if someone returns with the same question for Android platform, you cannot use the inbuilt remove() method if you are targeting for Android API-18 or less. The remove() method is added on API level 19. Thus, the best possible thing to do is to extend the JSONArray to create a compatible override for the remove() method.

public class MJSONArray extends JSONArray {

    @Override
    public Object remove(int index) {

        JSONArray output = new JSONArray();     
        int len = this.length(); 
        for (int i = 0; i < len; i++)   {
            if (i != index) {
                try {
                    output.put(this.get(i));
                } catch (JSONException e) {
                    throw new RuntimeException(e);
                }
            }
        } 
        return output;
        //return this; If you need the input array in case of a failed attempt to remove an item.
     }
}

EDIT As Daniel pointed out, handling an error silently is bad style. Code improved.

edited Mar 11 '15 at 18:45

answered Jan 28 '14 at 03:36

C--

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This is bad coding style. In case of an error, the element is not removed, but the invoking code has no chance to know this. a better way is to _not_ use try..catch but using `throws JSONException` in the function header – Daniel Alder Feb 14 '14 at 12:08
1

@DanielAlder The `remove` method can't throw an Exception because the overridden method doesn't do so. – C-- Feb 14 '14 at 12:43
1

Ok, in this case I would put a `throw new RuntimeException(e)` (or `InternalError`) instead of `e.printStackTrace();return this;` - just for case – Daniel Alder Feb 15 '14 at 20:37
It is not recommended to extend the default class. Better to create the `remove()` method in the class where you are using it. – Stack Overflow Nov 29 '19 at 23:09

Fabio Guerra · Answer 3 · 2017-09-05T00:54:45.840

4

public static JSONArray RemoveJSONArray( JSONArray jarray,int pos) {

JSONArray Njarray=new JSONArray();
try{
for(int i=0;i<jarray.length();i++){     
    if(i!=pos)
        Njarray.put(jarray.get(i));     
}
}catch (Exception e){e.printStackTrace();}
return Njarray;

}

edited Sep 05 '17 at 00:54

answered Nov 27 '13 at 19:09

Fabio Guerra

722
6
13

score 3 · Answer 4 · answered Jun 25 '15 at 06:34

 JSONArray jArray = new JSONArray();

    jArray.remove(position); // For remove JSONArrayElement

Note :- If remove() isn't there in JSONArray then...

API 19 from Android (4.4) actually allows this method.

Call requires API level 19 (current min is 16): org.json.JSONArray#remove

Right Click on Project Go to Properties

Select Android from left site option

And select Project Build Target greater then API 19

Hope it helps you.

score 2 · Answer 5 · answered Dec 17 '12 at 17:24

i guess you are using Me version, i suggest to add this block of function manually, in your code (JSONArray.java) :

public Object remove(int index) {
    Object o = this.opt(index);
    this.myArrayList.removeElementAt(index);
    return o;
}

In java version they use ArrayList, in ME Version they use Vector.

score 1 · Answer 6 · answered Nov 11 '15 at 03:45

You can use reflection

A Chinese website provides a relevant solution: http://blog.csdn.net/peihang1354092549/article/details/41957369
If you don't understand Chinese, please try to read it with the translation software.

He provides this code for the old version:

public void JSONArray_remove(int index, JSONArray JSONArrayObject) throws Exception{
    if(index < 0)
        return;
    Field valuesField=JSONArray.class.getDeclaredField("values");
    valuesField.setAccessible(true);
    List<Object> values=(List<Object>)valuesField.get(JSONArrayObject);
    if(index >= values.size())
        return;
    values.remove(index);
}

score 1 · Answer 7 · answered Dec 28 '16 at 18:15

In my case I wanted to remove jsonobject with status as non zero value, so what I did is made a function "removeJsonObject" which takes old json and gives required json and called that function inside the constuctor.

public CommonAdapter(Context context, JSONObject json, String type) {
        this.context=context;
        this.json= removeJsonObject(json);
        this.type=type;
        Log.d("CA:", "type:"+type);

    }

public JSONObject removeJsonObject(JSONObject jo){
        JSONArray ja= null;
        JSONArray jsonArray= new JSONArray();
        JSONObject jsonObject1=new JSONObject();

        try {
            ja = jo.getJSONArray("data");

        } catch (JSONException e) {
            e.printStackTrace();
        }
        for(int i=0; i<ja.length(); i++){
            try {

                if(Integer.parseInt(ja.getJSONObject(i).getString("status"))==0)
                {
                    jsonArray.put(ja.getJSONObject(i));
                    Log.d("jsonarray:", jsonArray.toString());
                }


            } catch (JSONException e) {
                e.printStackTrace();
            }
        }
        try {
            jsonObject1.put("data",jsonArray);
            Log.d("jsonobject1:", jsonObject1.toString());

            return jsonObject1;
        } catch (JSONException e) {
            e.printStackTrace();
        }
        return json;
    }

score 0 · Answer 8 · edited Jan 07 '20 at 14:57

0

To Remove some element from Listview in android then it will remove your specific element and Bind it to listview.

BookinhHistory_adapter.this.productPojoList.remove(position);

BookinhHistory_adapter.this.notifyDataSetChanged();

edited Jan 07 '20 at 14:57

Mickael B.

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answered Jan 07 '20 at 13:36

Rakesh Jha

279
2
7

Sakthidasan J · Answer 9 · 2020-05-28T11:55:39.740

0

We can use iterator to filter out the array entries instead of creating a new  Array. 

'public static void removeNullsFrom(JSONArray array) throws JSONException {
                if (array != null) {
                    Iterator<Object> iterator = array.iterator();
                    while (iterator.hasNext()) {
                        Object o = iterator.next();
                        if (o == null || o == JSONObject.NULL) {
                            iterator.remove();
                        }
                    }
                }
            }'

edited May 28 '20 at 11:55

answered May 28 '20 at 10:23

Sakthidasan J

1
2

Welcome to StackOverflow! Please make sure to add an explain to your answer to help others understand it – Markus May 28 '20 at 11:47
Hope It will solve issue but please add explanation of your code with it so user will get perfect understanding which he/she really wants. – Jaimil Patel May 28 '20 at 11:54

score 0 · Answer 10 · answered Apr 22 '21 at 06:03

static JSONArray removeFromJsonArray(JSONArray jsonArray, int removeIndex){
    JSONArray _return = new JSONArray();
    for (int i = 0; i <jsonArray.length(); i++) {
        if (i != removeIndex){
            try {
                _return.put(jsonArray.getJSONObject(i));
            } catch (JSONException e) {
                e.printStackTrace();
            }
        }
    }
    return _return;
}

score 0 · Answer 11 · answered Aug 09 '23 at 05:45

To remove multiple positions

    public static void main(String[] args) throws JSONException {
        JSONArray array = new JSONArray();
        array.put(0, "0");
        array.put(1, "1");
        array.put(2, "2");
        array.put(3, "3");
        List<Integer> toRemove = new ArrayList<>();
        toRemove.add(1);
        toRemove.add(0);
        toRemove = toRemove.stream().sorted().collect(Collectors.toList());
        int removedCount = 0; // Once we remove the element from array, we should reduce the position also with the removed item size
        for (int position : toRemove) {
            int newPosition = position - removedCount;
            array.remove(newPosition);
            removedCount = removedCount + 1;
            
        }
        System.out.println(array.toString());// ["2","3"]
    }

I see this is your first answer, which is awesome. But since there's already an accepted answer, new answers should try to improve on it, or at least update outdated information. So, why do you think that your solution is better than the **already accepted answer**? — Diego Borba, Aug 11 '23 at 13:27
As it’s currently written, your answer is unclear. Please [edit] to add additional details that will help others understand how this addresses the question asked. You can find more information on how to write good answers [in the help center](/help/how-to-answer). — Community, Aug 13 '23 at 01:13

How do I remove a specific element from a JSONArray?

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