json_encode（json_encode（array））

Question

I'm trying to create a PHP script to generate JSON data for a jqplot bubble chart. The jqplot sample code requires data in the format

var arr = [ 
  [45, 92, 1067, {label:"Alfa Romeo", color:'skyblue'}], 
  etc.
];

My script is along the lines of

while ...
  array_push(
    $arrBubble, 
    array(
      11, 
      123, 
      1236,
      json_encode(
        array('label' => $car, 'color' => 'skyblue')
      )
  );
} 
echo json_encode($arrBubble);

The problem is that the result is

[ [11, 123, 1236, "{\"label\":"VW", \"color\":\"skyblue\"}"] ]

The double json_encode has encoded the object(?) as a literal string.

What's the best way to work around this?

Answer 1

There is no reason to explicitly have a json_encode for one of the values inside the array. When you're using json_encode , it'll convert each level of the array as you expect.

var_dump(json_encode([
  11, 
  123, 
  1236,
  ['label' => $car, 'color' => 'skyblue']
]));

Outputs the structure you want:

string(48) "[11,123,1236,{"label":"VW","color":"skyblue"}]"