$re = '/(?x-i) # FREE-SPACE MODE, case-sensitive
(?(DEFINE)
(?<ws>[\r\n\t\x20]*)
(?<str>"(?:\\\\[rntbf\\\\\/] | [[:xdigit:]]{4} | [^\\\\"[:cntrl:]])*")
(?<bool>true|false)
(?<nil>nil)
(?<num>-?\d+(?:\.\d+)?)
(?<elem>(?:(?&str)|(?&bool)|(?&nil)|(?&num))(?&ws))
(?<comma>,(?&ws))
)
# JSON Array
\[ (?&ws)
(?:
(?:
(?&elem) | (?R)(?&ws)
)
(?(?=(?&comma)(?:(?&elem)|[\[\{]))(?&comma))
)*
\]
| # Or
# JSON Object
\{ (?&ws)
(?:
(?&str) (?&ws)
: (?&ws)
(?:
(?&elem) | (?R)(?&ws)
)
(?(?=(?&comma)["\[\{])(?&comma))
)*
\}/m';
$str = '{"foo":"bar", "bools":true,
"digits":42,
"objects":{ "cool" : "beans"},
"arraystoo":[
{"thisworks":"yep"},
{"thisworkstoo":"uh, huh!!"}
]
}';
preg_match_all($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