Get value of JSON array

This is the json array I have and I decode it using json_decode() of php

{"form":{"fieldsets":[{"fieldset_name":"name_1","datapoints":{"dp_id_1":1,"dp_id_2":4}},{"fieldset_name":"name_2","datapoints":{"dp_id_3":1,"dp_id_4":5}}]}}.

After decoding the array I obtained is

Array ( 
    [form] => Array ( 
        [fieldsets] => Array ( 
            [0] => Array ( 
                [fieldset_name] => name_1 
                [datapoints] => Array ( 
                    [dp_id_1] => 1 
                    [dp_id_2] => 4 
                ) 
            ) 
   开发者_开发技巧         [1] => Array ( 
                [fieldset_name] => name_2 
                [datapoints] => Array ( 
                    [dp_id_3] => 1 
                    [dp_id_4] => 5 
                ) 
            ) 
        ) 
    ) 
) 

Now I want to push datapoints array dp_id_1,dp_id_2 elements into one array and dp_id_3,dp_id_4 into other array

Please help me........

Simply loop over the array:

$points = array();

for($array['form']['fieldsets'] as $set) {
    $points = array_merge($points, $set['datapoints']);
}

Update:

Regarding your edit, then it is even simpler. Replace the body with:

$points[] = $set['datapoints'];

I suggest to read about arrays in PHP to get a better understanding on how they work.