is_numeric_string an hexadecimal numbers ("123" == "0x7B")

Hi internals! The internal is_numeric_string [1] function is used to check whether a string contains a number (and to extract that number). Currently is_numeric_string also accepts hexadecimal strings [2] (apart from the normal decimal integers and doubles). This can cause some quite odd behavior at times. E.g. string comparisons also use is_numeric_string, resulting in the behavior: var_dump('123' == '0x7b'); // true In all other parts of the engine hexadecimal strings are not recognized [3]: var_dump((int) '0x7b'); // int(0) This also causes minor problems in other parts of the engine where is_numeric_string is used. E.g. $string = 'abc'; var_dump($string['0xabc']); // string("a") // 0xabc is first accepted as a number by is_numeric_string, but then cast to 0 by convert_to_long But: $string = 'abc'; var_dump($string['0abc']); // outputs (as expected): Notice: A non well formed numeric value encountered in /code/8KXrYZ on line 9 NULL In my eyes accepting hex strings in is_numeric_string leads to a quite big WTF effect and causes problems and as such should be dropped. I don't think this has much BC impact, so it should be possible to change it. Nikita [1]: http://lxr.php.net/xref/PHP_TRUNK/Zend/zend_operators.h#is_numeric_string [2]: http://lxr.php.net/xref/PHP_TRUNK/Zend/zend_operators.h#131 [3]: http://www.php.net/manual/en/language.types.string.php#language.types.string.conversion