PHP: How to traverse through a JSON Object

JSON has become just as big as XML in terms of being the format used to transfer data between AJAX driven web services, meaning that as a PHP developer you will no doubt be doing a lot of dealing with JSON objects.

The default way of grabbing JSON data returned by a web service is to call the built in json_decode function which generates what is known as a stdClass. These can be traversed much as you would a normal array using loops:

$jsondatastdclass = json_decode($jsoninput);
print_r($jsondataarray);

foreach ($jsondatastdclass as $object)
{
  foreach ($object as $property=>$value)
   {
     echo $property." has the value ". $value;
   } 
}

It’s not great, but it does work. However, later version of PHP do allow you to add a second parameter when calling the json_decode function, namely a boolean which then forces the function to return a normal associative array.

In practice:

$jsondataarray = json_decode($jsoninput, true);
print_r($jsondataarray);

echo $jsondataarray['data'][0];

And now you know.