$re = '/^ {0,3}((?:(`){3,}?)|(?:(~){3,}?))(?!\2\3)(?:([^`\n]+?)(\1(?:\2\3)*)|(?:( *([^ \n]+)[^`\n]*)?\n([\s\S]*?)(^ {0,3}))(\1(?:\2\3)*)(?=$))/m';
$str = '```js
var test = \'test\';
```
```js
var x = "John Doe";
console.log( x );
```';
preg_match_all($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