Indicates whether a Key or Key Prefix is existing.
@access		public
@param		string		$key		Key in Dictionary
@return		bool
180833
public function has( $key )
	{
		if( empty( $key ) )																		//  no Key given
			throw new InvalidArgumentException( 'Key must not be empty.' );						//  throw Exception
		if( isset( $this->pairs[$key] ) )														//  Key is set on its own
			return TRUE;
		else																					//  Key has not been found
		{
			$key		.= $this->divider;														//  prepare Prefix Key to seach for
			foreach( $this->pairs as $pairKey => $pairValue )									//  iterate all stores Pairs
			{
				if( $pairKey[0] !== $key[0] )													//  precheck for Performance
					continue;																	//  skip Pair
				if( strpos( $pairKey, $key ) === 0 )											//  Prefix Key is found
					return TRUE;
			}
		}
		return FALSE;
	}
1225151
public function has($key)
    {
        if (!$this->isEnabled()) {
            return false;
        }

        return (null !== eaccelerator_get($this->prefix() . $key));
    }
727280
public function has(string $key): bool
    {
        return isset($this->data[$key]) || array_key_exists($key, $this->data);
    }
1155245
public function containsKey($key)
    {
        if (!$this->enabled)
            return false;

        $has_key = (eaccelerator_get($this->key($key)) !== null);

        $this->Logger->debug("Cache contains {$key}? " . (($has_key) ? 'TRUE' : 'FALSE'));

        return $has_key;
    }
400689
public function has(string $key): bool
    {
        return array_key_exists(strtolower($key), $this->keyMap) &&
            array_key_exists($this->keyMap[strtolower($key)], $this->collection);
    }
301211
function has($key)
    {
        return (array_key_exists($key, $this->properties)) && $this->properties[$key] !== null;
    }
397443
public function hasConfigurationKey($key)
    {
        $result = true;
        $configuration = $this->getConfiguration();

        $pathParts = explode(self::DELIMITER, $key);
        foreach ($pathParts as $pathPart) {
            if (array_key_exists(ucfirst($pathPart), $configuration) === false) {
                $result = false;
                break;
            } else {
                $configuration = $configuration[ucfirst($pathPart)];
            }
        }

        return $result;
    }
262659
private function isPrefixedKey($key)
    {
        if (strlen($key) > 1) {
            if (substr($key, 0, 1) == '_') {
                try {
                    intval(substr($key, 1, strlen($key) - 1));

                    return true;
                } catch (\Exception $e) {
                    return false;
                }
            }
        }
    }
743996
public function containsKey($key)
    {
        if (!$this->enabled)
            return false;

        $has_key = false;

        $fetchMethod = $this->apcFuncPrefix.'_fetch';
        $fetchMethod($this->key($key), $has_key);

        // $this->Logger->debug("Cache contains {$key}? " . (($has_key) ? 'TRUE' : 'FALSE'));

        return $has_key;
    }
207676
public function has($key)
    {
        //~ Check if enabled
        if (!$this->isEnabled()) {
            return false;
        }

        //~ Clear expired Cache files
        $this->clearExpired();

        $key = $this->prefix() . $key;

        return isset($this->cache[$key]);
    }
928616
private function prefixKey($key)
    {
        $first = explode('.', $key)[0];
        $isRootNode = in_array($first, $this->rootNodes, true);

        return $isRootNode ? 'config.'.$key : $key;
    }
1239417
public function has($key)
    {
        if (!$this->isEnabled()) {
            return false;
        }

        return (false !== apc_fetch($this->prefix() . $key));
    }
698705
public function exists(string $key): bool
    {
        return $this->handle->hExists($this->name, $key);
    }
1346603
public function exists($key) {

        $stmt = $this->connection->query("SELECT `key` FROM ".$this->table." WHERE `key`='{$key}';");
        $res  = $stmt->fetch(\PDO::FETCH_ASSOC);

        return isset($res["key"]);
    }
1086491
public function has($key)
    {
        $key = trim($key, '.');
        if (strpos($key, '.') !== false) {
            $array =& $this->_items;
            foreach (explode('.', $key) as $v) {
                if (!isset($array[$v]))
                    return false;
                else
                    $array =& $array[$v];
            }
            return true;
        } else {
            return array_key_exists($key, $this->_items);
        }
    }
1116432
protected function setKey($key) {
        $this->key = $this->settings['prefix'].$key.$this->settings['suffix'];
        return true;
    }
566699
public function hasKey(string $key): bool
    {
        return $key && strpos($key, '@@') === false && file_exists($this->getPathFromKey($key));
    }