<?php $m1 = new Memcached('id1'); $m1->setOption(Memcached::OPT_PREFIX_KEY, "foo_"); var_dump($m1->isPersistent()); $m1 = new Memcached('id1'); var_dump($m1->isPersistent()); $m2 = new Memcached('id1'); var_dump($m2->isPersistent()); // this change affects $m1 $m2->setOption(Memcached::OPT_PREFIX_KEY, "bar_"); $m3 = new Memcached('id2'); var_dump($m3->isPersistent()); $m3 = new Memcached(); var_dump($m3->isPersistent()); // objects have the same resource, but they are not the same object. var_dump($m1 === $m2); var_dump($m1->getOption(Memcached::OPT_PREFIX_KEY));