(PECL apcu >= 5.0.0)
APCUIterator::__construct — Constructs an APCUIterator iterator object
$search = null
   [, int $format = APCU_ITER_ALL
   [, int $chunk_size = 100
   [, int $list = APCU_LIST_ACTIVE
  ]]]] )Constructs an APCUIterator object.
search
      A PCRE regular expression that
      matches against APCu key names, either as a string for
      a single regular expression, or as an array of regular
      expressions. Or, optionally pass in NULL to skip the search.
     
formatThe desired format, as configured with one or more of the APCU_ITER_* constants.
chunk_sizeThe chunk size. Must be a value greater than 0. The default value is 100.
list
      The type to list. Either pass in APCU_LIST_ACTIVE
      or APCU_LIST_DELETED.
     
   An APCUIterator object on success,
   or NULL on failure.
  
Example #1 A APCUIterator::__construct() example
<?php
foreach (new APCUIterator('/^counter\./') as $counter) {
    echo "$counter[key]: $counter[value]\n";
    apc_dec($counter['key'], $counter['value']);
}
?>