在php中将对象转换为JSON的问题

I need to convert an object into JSON using a php script.

I wrote this code in a loop cycle:

$zaino->rows[$num_oggetti]->item = $oggetto;
$zaino->rows[$num_oggetti]->amount = $num;

After the loop cycle I convert the object into json: json_encode($zaino);

This is what I get:

{"rows":{"1":{"item":"Soffio di Morte","amount":"1"},"2":{"item":"Pietra Anima di Ferro","amount":"11"},"3":{"item":"Pietra Anima di Legno","amount":"12"}}

But I need something like:

{"rows":[{"item":"Soffio di Morte","amount":"1"},{"item":"Pietra Anima di Ferro","amount":"11"},{"item":"Pietra Anima di Legno","amount":"12"}]}

without numbers between "", so that I can easily get the values using for example $zaino->rows[1]->item after calling a json_decode. How can I do it?

The problem is that $num_oggetti is a string value, not a number (yes, numeric, but not a number). This tells PHP that you are setting a key instead of an index.

If you do not need the actual index you could do something like:

$zaino->rows[] = [
  'item'   => $oggetto,
  'amount' => $num
];

This way you leave the index generation entirely up to PHP and you'll get the json output you want.