php man page for preg_filter

PREG_FILTER(3)								 1							    PREG_FILTER(3)

preg_filter - Perform a regular expression search and replace

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

DESCRIPTION
       preg_filter(3)  is  identical  to  preg_replace(3)  except it only returns the (possibly transformed) subjects where there was a match. For
       details about how this function works, read the preg_replace(3) documentation.

RETURN VALUES
	Returns an array if the $subject parameter is an array, or a string otherwise.

	If no matches are found or an error occurred, an empty array is returned when $subject is an array or NULL otherwise.

EXAMPLES
       Example #1

	       Example comparing preg_filter(3) with preg_replace(3)

	      <?php
	      $subject = array('1', 'a', '2', 'b', '3', 'A', 'B', '4');
	      $pattern = array('/d/', '/[a-z]/', '/[1a]/');
	      $replace = array('A:$0', 'B:$0', 'C:$0');

	      echo "preg_filter returns
";
	      print_r(preg_filter($pattern, $replace, $subject));

	      echo "preg_replace returns
";
	      print_r(preg_replace($pattern, $replace, $subject));
	      ?>

	      The above example will output:

	      preg_filter returns
	      Array
	      (
		  [0] => A:C:1
		  [1] => B:C:a
		  [2] => A:2
		  [3] => B:b
		  [4] => A:3
		  [7] => A:4
	      )
	      preg_replace returns
	      Array
	      (
		  [0] => A:C:1
		  [1] => B:C:a
		  [2] => A:2
		  [3] => B:b
		  [4] => A:3
		  [5] => A
		  [6] => B
		  [7] => A:4
	      )

SEE ALSO
       PCRE Patterns, preg_quote(3), preg_replace(3), preg_replace_callback(3), preg_grep(3), preg_last_error(3).

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