php preg-replace致命情况

Question

i need to transform nubmer to string (dividing each 3 numbers by space, ie 20000 => 20 000 , 1400000 => 1 400 000 )

my code:

$cena = '20000';

$cena = preg_replace('/\\D+/g', '', $cena);

$cena = preg_replace('/\\d(?=(?:\\d{3})+(?!\\d))/g', '$& ', $cena);

this results in:

Warning: preg_replace() [function.preg-replace]: Unknown modifier 'g' in myfile.php on line xxx

what's wrong?

Answer 1

$number=1400000;
$format = number_format($number, 0, '', ' ');

echo $format; //1 400 000

Answer 2

I'm assuming you're trying to do a global replace using the g modifier. preg_replace doesn't support a g modifier, hence the error you're getting.

Instead, preg_replace takes an optional limit parameter which determines the maximum number of replacements that will be done. It defaults to -1, which means unlimited. In other words, it's already doing what you're trying to do.

From the manual page:

mixed preg_replace ( mixed $pattern , mixed $replacement ,
                     mixed $subject [, int $limit = -1 [, int &$count ]] )