JSON and PHP arrays

Question

json_encode(array(
    array(0 => "431.940054495913"),
    array(1 => "431.940054495913"),
));

Is rendered like this:

[
    ["431.940054495913"],
    {"1":"431.940054495913"}
]

Why are the two arrays rendered differently ?

Answer 1

Any PHP array that can be rendered as a JSON array will be rendered as a JSON array: Any PHP array having only sequential numeric keys starting from 0 will be rendered as a JSON array.

This is the case for the first array: array(0 => "431.940054495913").

How to fix this

• The JSON_FORCE_OBJECT flag will render all PHP arrays as JSON objects

  json_encode(array(0 => "431.940054495913"), JSON_FORCE_OBJECT);
  // {"0": "431.940054495913"}
  
  json_encode(array(0 => "431.940054495913"));
  // ["431.940054495913"]
  

• Alternatively, you could convert your PHP array to a PHP object:

  json_encode( (object) array(0 => "431.940054495913"));
  // {"0": "431.940054495913"}
  

  (if you don't want to render every array as object or if you don't have JSON_FORCE_OBJECT)