(PECL memcache >= 0.2.0)
Memcache::replace — Replace value of the existing item
Memcache::replace() should be used to replace value of
existing item with key. In case if item with such
key doesn't exists, Memcache::replace() returns
FALSE. For the rest Memcache::replace() behaves
similarly to Memcache::set().
Also you can use memcache_replace() function.
key
The key that will be associated with the item.
var
The variable to store. Strings and integers are stored as is, other types are stored serialized.
flag
Use MEMCACHE_COMPRESSED to store the item
compressed (uses zlib).
expire
Expiration time of the item. If it's equal to zero, the item will never expire. You can also use Unix timestamp or a number of seconds starting from current time, but in the latter case the number of seconds may not exceed 2592000 (30 days).
Returns TRUE on success or FALSE on failure.
Example #1 Memcache::replace() example
<?php
$memcache_obj = memcache_connect('memcache_host', 11211);
/* procedural API */
memcache_replace($memcache_obj, "test_key", "some variable", false, 30);
/* OO API */
$memcache_obj->replace("test_key", "some variable", false, 30);
?>