json_encode（）PHP的不同结果

Question

If i do this :

$new_arr = array(
0 => 'keyboard',
1 => 'mouse',
2 => 'computer'
);

print_r(json_encode($new_arr));

Output:

["keyboard","mouse","computer"]

But say i fetch all rows of "product" table from my database and i do this :

$product_with_id_map = array();
foreach($query as $result) {
$product_with_id_map[$result->id] = $result->name;
}
print_r(json_encode($product_with_id_map));

Output:

{"0":"Keyboard","1":"mouse","2":"computer"}

I really need to retain the key of the array when i json_encode also can you tell me how to achieve the second output in the 1st example ?

Answer 1

Cast the array to object.

$new_arr = array(
  0 => 'keyboard',
  1 => 'mouse',
  2 => 'computer'
);

print_r(json_encode((object)$new_arr));
// output: {"0":"keyboard","1":"mouse","2":"computer"}

Addtion: If you use this result in javascript, I suggest you use the array, array is also object in javascript, besides, it provide more methods and length property to you.