{
  "testing":{
    "number-1":{
      "b":1,
    },
    "number-2":{
      "b":1,
    },
}{
  "testing":[{
    "number-1":{
      "b":1,
    },
    "number-2":{
      "b":1,
    }]
}$array['testing'] = [];
    foreach ($testing as $item)
    {
        $name = 'number-'.$item['id'];
        $f[$name]  =   [
            'b'    =>  $item['rooms'],
        ];
        array_push($array['testing'], $f);
    }