Returns TRUE if the data item exists. FALSE otherwise.

@param string $key The key of the stored data item.
@return bool TRUE if the data item exists. FALSE otherwise.
@throws \Exception
@throws \BearFramework\App\Data\DataLockedException
13512
public function exists(string $key): bool
    {
        $result = $this->execute([
            [
                'command' => 'get',
                'key' => $key,
                'result' => ['key']
            ]
        ]);
        return isset($result[0]['key']);
    }
521394
public function contains($key)
    {
        return isset($this->_data[$key]) || array_key_exists($key, $this->_data);
    }
188633
public function exists($key)
	{
		return isset($this->data[$key]) && ($this->data[$key][1] > time());
	}
728388
public static function exists($key)
    {
        $key = explode('.', $key);
        $array = self::$arr[$key[0]];
        unset($key[0]);

        foreach ( $key as $k ) {
            if ( is_array(self::$arr) ) {
                $array = $array[$k];
            } else {
                return false;
            }
        }

        if ( !is_null($array) ) {
            return true;
        } else {
            return false;
        }
    }
619117
public function exist($key) : bool
    {
        return $this->get($key, false) !== false
               && $this->get($key, true) !== true;
    }
242177
public function do_exists($key)
    {
        $redis = is_object($this->_redis) ? $this->_redis : $this->_getRedis();
        return (bool)$redis->exists($this->_prefix . $key);
    }
972765
protected function checkKeyExists($data, $key)
    {
        if (!$data->has($key)) {
            $this->output->writeln("<error>The key $key does not exist.");

            return false;
        }

        return true;
    }
682012
public function offsetExists($key)
    {
        if (isset($this->firstItems[$key])) {
            return true;
        }

        if (isset($this->lastItems[$key])) {
            return true;
        }

        $record = $this->list->find($this->keyField, $key);

        return $record != null;
    }
417126
public function has($key)
    {
        $keys = explode('.', (string)$key);
        $data = &$this->data;
        foreach ($keys as $key) {
            if (!isset($data[$key])) {
                return false;
            }
            $data = &$data[$key];
        }

        return true;
    }
882849
public function __isset( $key ) 
	{
		return ( array_key_exists( $key, $this->_data_store ) || method_exists( $this, '_get_modifier_'.$key ) ) ? true : false;
	}
955785
public function containsKey(string $key): bool
    {
        if (isset($this->orgData[$key])) {
            return ! isset($this->removeAttributes[$key]);
        } else {
            return isset($this->addAttributes[$key]);
        }
    }
120147
public function offsetExists($key)
    {
        $key = strtr(strtolower($key), '_', '-');

        return array_key_exists($key, $this->_data);
    }
337118
protected static function checkDatabase($key)
    {
        $driver = self::$params['database']['default'];
        //
        if (array_key_exists($key, self::$params['database'])) {
            return true;
        } elseif (array_key_exists($key, self::$params['database']['connections'][$driver])) {
            return true;
        } else {
            self::exception('database', $key);
        }
    }
1272101
public function exists( $key ) {
		return ( is_array( $this->data ) && array_key_exists( $key, $this->data ) ) ||
			( is_object( $this->data ) && property_exists( $this->data, $key ) );
	}
288391
public function has(string $key){
        $data   = $this->status() === self::ACTIVE
            ? $_SESSION : $this->finishedData;
        
        return array_key_exists($key, $data);
    }
113950
public function exists($key) {
        $key = $this->secureKey($key);
        
        if (isset($_SESSION[$key])) return true;
        
        return false;
    }
375673
public function has($key): bool
    {
        return $this->exists($key) && null !== $this->attributes[$key];
    }