How do I replace multiple characters with the same number of characters with a regular expression?

Question

I\'ve got the following source:

011011000010011011&         


        

Answer 1

Try this here

0110110000100110110110';
$pattern = '/(?<=)( *?)[10](?=.*?<\/font>)/';
$replacement = '$1 ';
while (preg_match($pattern, $string)) {
        $string = preg_replace($pattern, $replacement, $string);
}
echo $string;

I use a positive look behind (?<=) to search for the color part. And a positive look ahead (?=.*?<\/font>) for the end.

Then I match the already replaced spaces and put them into group 1 and then the [10].

Then I do a while loop until the pattern do not match anymore and a replace with the already replaces spaces and the new found space.