(PHP 5 >= 5.2.0)
RegexIterator::setMode — Sets the operation mode.
$mode
   )Sets the operation mode.
modeThe operation mode.
The available modes are listed below. The actual meanings of these modes are described in the predefined constants.
| value | constant | 
|---|---|
| 0 | RegexIterator::MATCH | 
| 1 | RegexIterator::GET_MATCH | 
| 2 | RegexIterator::ALL_MATCHES | 
| 3 | RegexIterator::SPLIT | 
| 4 | RegexIterator::REPLACE | 
No value is returned.
Example #1 RegexIterator::setMode() example
<?php
$test = array ('str1' => 'test 1', 'test str2' => 'another test', 'str3' => 'test 123');
$arrayIterator = new ArrayIterator($test);
// Filter everything that starts with 'test ' followed by one or more numbers.
$regexIterator = new RegexIterator($arrayIterator, '/^test (\d+)/');
// Operation mode: Replace actual value with the matches
$regexIterator->setMode(RegexIterator::GET_MATCH);
foreach ($regexIterator as $key => $value) {
    // print out the matched number(s)
    echo $key . ' => ' . $value[1] . PHP_EOL;
}
?>
The above example will output something similar to:
str1 => 1 str3 => 123