apcu_exists

Checks if entry exists

&reftitle.description; ``bool``array```apcu_exists` ``string``array```keys`

Checks if one or more APCu entries exist.

&reftitle.parameters;

`keys`

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

&reftitle.returnvalues;

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.

&reftitle.examples;

### `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);

    ?>

&example.outputs.similar;

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

&reftitle.seealso;

- `apcu_cache_info`
- `apcu_fetch`