Memcached::add

(PECL memcached >= 0.1.0)

Memcached::add — Add an item under a new key

public bool Memcached::add ( string $key , mixed $value [, int $expiration ] )

Memcached::add() is similar to Memcached::set, but the operation fails if the key already exists on the server.

key: The key under which to store the value.
value: The value to store.
expiration: The expiration time, defaults to 0. See Expiration Times for more info.

如果成功则返回 TRUE，失败则返回 FALSE。 The Memcached::getResultCode will return Memcached::RES_NOTSTORED if the key already exists.