$re = '/^( *)("(?:[^"]|\\\\")+": )?(\[(?:\s+\d+,)*\s+\d+\s+\])/m';
$str = '{
"foo": "bar",
"oneLine": [
1,
2,
3
],
"another\\"Line": [
1,
2,
3
],
"multipleLines": [
{
"name": "X",
"alsoOneLine": [
4,
5,
6
],
"inner": [
[
1,
2,
3
],
[
4,
5,
6
]
]
},
{
"name": "Y"
}
]
}';
preg_match_all($re, $str, $matches, PREG_SET_ORDER, 0);
// Print the entire match result
var_dump($matches);
Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for PHP, please visit: http://php.net/manual/en/ref.pcre.php