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<?php $old = '{"4":{"deu":1, "eng":1, "fra":1}}'; $new = '{"4":{"deu":1, "eng":2}}'; $oldArray = json_decode($old,true); $newArray = json_decode($new,true); $finalArray =[]; foreach($oldArray as $key=>$value){ $finalArray[$key] = array_merge($value,$newArray[$key]); } print_r($finalArray); echo json_encode($finalArray);
Output for 7.3.0 - 7.3.33, 7.4.0 - 7.4.33, 8.0.0 - 8.0.30, 8.1.0 - 8.1.27, 8.2.0 - 8.2.17, 8.3.0 - 8.3.4
Array ( [4] => Array ( [deu] => 1 [eng] => 2 [fra] => 1 ) ) {"4":{"deu":1,"eng":2,"fra":1}}

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