apcu_exists

(PECL apcu >= 4.0.0)

apcu_exists — Checks if entry exists

说明

apcu_exists(mixed $keys): mixed

Checks if one or more APCu entries exist.

参数

keys: A string, or an array of strings, that contain keys.

返回值

Returns true if the key exists, otherwise false Or if an array was passed to keys, then an array is returned that contains all existing keys, or an empty array if none exist.

范例

示例 #1 apcu_exists() example


<?php
$fruit  = 'apple';
$veggie = 'carrot';

apcu_store('foo', $fruit);
apcu_store('bar', $veggie);

if (apcu_exists('foo')) {
    echo "Foo exists: ";
    echo apcu_fetch('foo');
} else {
    echo "Foo does not exist";
}

echo PHP_EOL;
if (apcu_exists('baz')) {
    echo "Baz exists.";
} else {
    echo "Baz does not exist";
}

echo PHP_EOL;

$ret = apcu_exists(array('foo', 'donotexist', 'bar'));
var_dump($ret);

?>

以上例程的输出类似于：

Foo exists: apple
Baz does not exist
array(2) {
  ["foo"]=>
  bool(true)
  ["bar"]=>
  bool(true)
}

参见

apcu_cache_info() - 从 APCu 存储中获取缓存信息
apcu_fetch() - Fetch a stored variable from the cache

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