Question

Would like to ask about how do I write a preg_replace in PHP to remove everything except Integers, ‘:’ (the 1st colon encountered).

An example:

one (1) dog : four (4) cat sharing a drink costing USD0.40 or 40 cents.

to

1:4

Answer 1

Here are two examples:

    $input  = 'one (1) dog : four (4) cat sharing a drink costing USD0.40 or 40 cents.';
    $regex  = '~.*?(?P<first>\d+).*?:.*?(?P<second>\d+).*~s';
    $result = preg_replace($regex, '$1:$2', $input);

    echo $result;

    if (preg_match($regex, $input, $matches)) {
      $result = $matches['first'] .':'. $matches['second'];
    }

preg_replace() and preg_match() both will end up with same results.