php - How do I compare object values that are inside an array? -

i have array containing several objects.

$products = [             {"id":"1","random":"sadasd","mergethis":"ding"},             {"id":"2","random":"assdfsadf","mergethis":"ding"},             {"id":"2","random":"assdfsadf","mergethis":"flop"},             {"id":"2","random":"assdfsadf","mergethis":"bips"},             {"id":"3","random":"sdfss","mergethis":"flung"},             {"id":"3","random":"sdfss","mergethis":"rorg"},             {"id":"4","random":"asdasdddaf","mergethis":"shwung"}             ] 

i'm trying iterate trough array , when id allready present in array, want add value of mergethis first hit has same id, seperated comma, , unset object array.

so expected outcome become:

[ {"id":"1","random":"sadasd","mergethis":"ding"}, {"id":"2","random":"assdfsadf","mergethis":"ding,flop,bips"}, {"id":"3","random":"sdfss","mergethis":"flung,rorg"}, {"id":"4","random":"asdasdddaf","mergethis":"shwung"} ] 

i'm trying iterate trough $products , compare values i'm stuck @ comparing value subvalue of array in stead of entire array

foreach($products $key => $value){     if (in_array($value->id, $products)) {         //delete item , add product_category comma sepereated first item         //unset($products[$key]);     } } 

this doesn't work because compares item entire array in stead of sub value id of array item.

how go getting expected outcome?

do need create new array filled keys , id values of each array item , iterate trough that? or there easier method compare object values inside array each other?

hint: use associative array id key , whole product value:

$results = array(); foreach ($products $prod){     if (array_key_exists($prod['id'], $results)){         $results[$prod['id']]['mergethis'] .= ',' . $prod['mergethis'];     } else {         $results[$prod['id']] = $prod;     } }