Prepend data to an existing item_脚本学堂

说明

public bool Memcached::prepend ( string $key , string $value )

Memcached::prepend() prepends the given value string to the value of an existing item. The reason that value is forced to be a string is that prepending mixed types is not well-defined.

Note: If the Memcached::OPT_COMPRESSION is enabled, the operation will fail and a warning will be issued, because prepending compressed data to a value that is potentially already compressed is not possible.

参数

key: The key of the item to prepend the data to.
value: The string to prepend.

返回值

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 does not exist.

范例

Example #1 Memcached::prepend() example


<?php
$m = new Memcached();
$m->addServer('localhost', 11211);
$m->setOption(Memcached::OPT_COMPRESSION, false);

$m->set('foo', 'abc');
$m->prepend('foo', 'def');
var_dump($m->get('foo'));
?>

上例将输出：

string(6) "defabc"

参见

Memcached::prependByKey - Prepend data to an existing item on a specific server
Memcached::append - Append data to an existing item