Java how to remove strings from JSONArray

Question

JSONArray jsonArray = new JSONArray();

jsonArray.put(1);
jsonArray.put("empty");
jsonArray.put(2);
jsonArray.put(3);
jsonArray.put("empty");
jsonArray.put(4);
jsonArray.put("empty");

lets say we have this jsonArray, there are strings empty, how to remove them without leaving gaps?

already we have link with solution http://stackoverflow.com/questions/18497162/how-to-remove-element-from-json-array — Karthikeyan Sukkoor, Dec 19 '13 at 12:38
@KarthikeyanSukkoor the link you pointed out is for javascript. The question is on Java and was tagged in java. There is no splice() in JsonArray in java. — AJJ, Dec 19 '13 at 13:11

score 2 · Accepted Answer · edited Sep 14 '18 at 12:52

2

You can use the following code :

for (int i = 0, len = jsonArray.length(); i < len; i++) {
    JSONObject obj = jsonArray.getJSONObject(i);
    String val = jsonArray.getJSONObject(i).getString();
    if (val.equals("empty")) {            
        jsonArray.remove(i);
    }
}

edited Sep 14 '18 at 12:52

Gastón Saillén

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answered Dec 19 '13 at 12:38

Sujith PS

4,776
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Keerthivasan · Answer 2 · 2013-12-19T12:53:24.467

You can use this following code

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 string equal to "empty"
        if (!"empty".equals(jsonArray.getString(i)) 
        {
            list.put(jsonArray.get(i));
        }
   } 
 //Now, list JSONArray has no empty string values
}

score 0 · Answer 3 · edited May 23 '17 at 11:56

0

take a look at this post. Make a list to put the indexes of the elements with the "empty" string and iterate over your list (the one with the "empty" elements) saving the indexes of the items to delete. After that, iterate over the previosly saved indexes and use

list.remove(position);

where position takes the value of every item to delente (within the list of index).

edited May 23 '17 at 11:56

Community

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1

answered Dec 19 '13 at 12:48

MRodriguez08

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1
7

score 0 · Answer 4 · edited Dec 19 '13 at 12:51

0

Should work with few fixes to Keerthi's code:

for (int i = 0; i < jsonArray.length(); i++) {
    if (jsonArray.get(i).equals("empty")) {
        jsonArray.remove(i);
    }
}

edited Dec 19 '13 at 12:51

Mr. Polywhirl

42,981
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answered Dec 19 '13 at 12:48

michali

401
2
11

Note that versions with getString() will not work because first element is not a String... – michali Dec 19 '13 at 13:00

score 0 · Answer 5 · answered Dec 19 '13 at 13:08

you can use string replace after converting the array to string as,

 JSONArray jsonArray = new JSONArray();
 jsonArray.put(1);
 jsonArray.put("empty");
 jsonArray.put(2);
 jsonArray.put(3);
 jsonArray.put("empty");
 jsonArray.put(4);
 jsonArray.put("empty");
 System.err.println(jsonArray);
 String jsonString = jsonArray.toString();
 String replacedString = jsonString.replaceAll("\"empty\",", "").replaceAll("\"empty\"", "");
 jsonArray = new JSONArray(replacedString);
 System.out.println(jsonArray);

Before replace:

jsonArray is [1,"empty",2,3,"empty",4,"empty"]

After replace:

jsonArray is [1,2,3,4]

Java how to remove strings from JSONArray

5 Answers5