On PHP >= 5.4 you can obtain your keys with one line of code:
$nodeNames = array_keys( json_decode( $jsonString, True )['result'][0] );
3v4l.org demo
On lower versions (PHP >= 5.2.16), you have to break above code in two lines:
$array = json_decode( $jsonString, True );
$nodeNames = array_keys( $array['result'][0] );
I decode the JSON string with second parameter as True to force result as array, then I call array_keys
to obtain the keys of array['result'][0]
.
Edit: more flexibility
Your example can be processed as above without problems, but what happens if original JSON string has different keys? The above solution will fail if in the first result
row there are not all the keys. To obtain all the keys, you can use this code:
$array = json_decode( $jsonString, True );
$nodeNames = array();
foreach( $array['result'] as $row )
{
$nodeNames = array_unique( array_merge( $nodeNames, array_keys( $row ) ) );
}
or, using array_filter
, with this code:
$array = json_decode( $jsonString, True );
$nodeNames = array();
array_filter
(
$array['result'],
function( $row )
{
global $nodeNames;
$nodeNames = array_unique( array_merge( $nodeNames, array_keys( $row ) ) );
}
);
By this two equivalent examples, I process each result
row, merging the keys in $nodeNames
array and using array_unique
to delete duplicate keys.