(PECL memcache >= 0.2.0)
Memcache::add -- memcache_add — Add an item to the server
Memcache::add() stores variable var with key only if such key doesn't exist at the server yet.
keyvarflagMEMCACHE_COMPRESSED to store the item compressed (uses zlib).expireReturns true on success or false on failure. Returns false if such key already exist. For the rest Memcache::add() behaves similarly to Memcache::set().
Example #1 Memcache::add() example
<?php
$memcache_obj = memcache_connect("localhost", 11211);
/* procedural API */
memcache_add($memcache_obj, 'var_key', 'test variable', false, 30);
/* OO API */
$memcache_obj->add('var_key', 'test variable', false, 30);
?>