Online PHP editor | refs for YGKMj

<?php foreach ( array( array('/\\d+/', '$0'), array('/\\d+/', '$01'), array('/\\d+/', '${0}1'), array('/(\\d+)/', '$0'), array('/(\\d+)/', '$01'), array('/(\\d+)/', '{$0}1'), array('/(\\d+)/', '$1'), array('/(\\d+)/', '$12'), array('/(^)(^)(^)(^)(^)(^)(^)(^)(^)(^)(^)(\\d+)/', '$12'), array('/(^)(^)(^)(^)(^)(^)(^)(^)(^)(^)(^)(\\d+)/', '$123'), ) as $list ) { list ($re, $replace) = $list; echo "$re '$replace' => '", preg_replace($re, $replace, "42"), "'\n"; }