Find the number of objects in a json array

Question

I have searched a lot and I found few methods to find the length of my JSON array. I have tried:

count
json.length

but these return 1, instead of the actual length. I want to show it using PHP.

My json is:

$huge = '[{"location":[{"building":["Default Building"],"name":"Default Location"}],"name":"Default Organization"},{"location":[{"building":["test_loc1_building1","test_loc1_building2"],"name":"test location1"},{"building":["test_loc2_building2"],"name":"test location2"}],"name":"test Organization"}]';

How can I find the number of objects in my JSON array?

JSON is a serialization format, what about de-serializing it and checking? — Benjamin Gruenbaum, Apr 08 '13 at 06:24
Here you have another solution without using json_decode. http://stackoverflow.com/questions/28772904/convert-json-string-to-array-without-json-decode — Luis Gerardo Mateos, Mar 10 '16 at 09:19
Here you have another solution without using json_decode: http://stackoverflow.com/questions/28772904/convert-json-string-to-array-without-json-decode — Luis Gerardo Mateos, Mar 10 '16 at 09:20

score 34 · Answer 1 · edited Dec 08 '14 at 21:02

34

You need to decode the json object and then count the elements in it ..

 $json_array  = json_decode($json_string, true);
 $elementCount  = count($json_array);

edited Dec 08 '14 at 21:02

AndyD273

7,177
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answered Apr 08 '13 at 06:35

alwaysLearn

6,882
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You can shorten this to one line by nesting `$elementCount = count(json_decode($json_string, true));` If you don't need $json_array as a PHP variable elsewhere. – AndyD273 Dec 08 '14 at 21:07
But that wouldn't work because it includes the brackets and quotes. – Agil Apr 23 '19 at 11:19

Stegrex · Answer 2 · 2013-04-08T08:19:29.463

6

You'll need to decode into PHP arrays before you do any work with the data.

Try:

$hugeArray = json_decode($huge, true); // Where variable $huge holds your JSON string.

echo count($hugeArray);

If you need to count to a lower depth, you'll need to iterate through the array.

For example, if you want to count the number of elements in the next layer, you can do:

foreach ($hugeArray as $key => $value) {
    echo $key.' - '.count($value);
}

However, this isn't necessarily meaningful because it depends on what you are trying to count, what your goal is. This block only counts the number of elements 1 layer underneath, regardless of what the actual numbers could mean.

edited Apr 08 '13 at 08:19

answered Apr 08 '13 at 06:26

Stegrex

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and now how can print the number of objects in each small array – user2201395 Apr 08 '13 at 06:39
@user2201395 Then you iterate through the array's elements and echo the count() of each element. – Stegrex Apr 08 '13 at 08:15

score 0 · Answer 3 · answered Apr 08 '13 at 06:27

First decode your json and after that use count on it.

$huge='[{"location":[{"building":["Default Building"],"name":"Default Location"}],"name":"Default Organization"},{"location":[{"building":["test_loc1_building1","test_loc1_building2"],"name":"test location1"},{"building":["test_loc2_building2"],"name":"test location2"}],"name":"test Organization"}]';
$arr = json_decode($huge,true);
echo count($arr);

score 0 · Answer 4 · answered Mar 13 '20 at 12:33

0

We can use ".sizeof()" function. So

answered Mar 13 '20 at 12:33

Lee ChengRi

1

score -1 · Answer 5 · answered Apr 08 '13 at 07:07

Object (an unordered collection of key:value pairs with the ':' character separating the key and the value, comma-separated and enclosed in curly braces; ...)

Wikipedia: JSON

So, all you have to do are just count opened curly braces.

substr_count($huge , '{');

But... If you are storing some strings with '{' in json you can't do it. In that way you have to write your own simple parser or regular expression.

But... the easies way to json_decode. And use recursive function if you want to get count of all objects in json.

function count_objects($value)
    {
    if (is_scalar($value) || is_null($value))
        $count = 0;
    elseif (is_array($value))
        {
        $count = 0;
        foreach ($value as $val)
            $count += count_objects($val);
        }
    elseif (is_object($value))
        {
        $count = 1;
        $reflection_object = new \ReflectionObject($value);
        foreach ($reflection_object->getProperties() as $property)
            {
            $count +=count_objects($property->getValue($value));
            }
        }

    return $count;
    }

$huge = '[{"location":[{"building":["Default Building"],"name":"Default Location"}],"name":"Default Organization"},{"location":[{"building":["test_loc1_building1","test_loc1_building2"],"name":"test location1"},{"building":["test_loc2_building2"],"name":"test location2"}],"name":"test Organization"}]';

echo count_objects(json_decode($huge));

Find the number of objects in a json array

5 Answers5