判断是否存在key.

@param string $key

@return bool
6039
public function has($key)
    {
        $result = $this->load($key);
        return Arr::has(static::$configs[$result[0]], $result[1]);
    }
704051
public function get(string $key)
    {
        if (empty($key) || !$this->isEnable()) {
            return false;
        }

        $value = $this->read();
        if (!is_array($value) || !isset($value[$key])) {
            return false;
        }

        return $value[$key];
    }
1249577
public function has(string $key): bool
    {
        return isset($this->data[ $key ]) && !empty($this->data[ $key ]);
    }
727280
public function has(string $key): bool
    {
        return isset($this->data[$key]) || array_key_exists($key, $this->data);
    }
513264
public function key($key)
    {
        if (!$key) {
            return false;
        }

        $prefix = '';
        if ($this->_groupPrefix) {
            $prefix = md5(implode('_', $this->groups()));
        }

        $key = preg_replace('/[\s]+/', '_', strtolower(trim(str_replace([DIRECTORY_SEPARATOR, '/', '.'], '_', (string)$key))));

        return $prefix . $key;
    }
308526
public function has($key): bool {
        $key = trim($key);
        $path = explode('.', $key);
        $pathLength = count($path);
        $target = &$this->data;
        for ($i = 1; $i <= $pathLength; ++$i) {
            $subKey = $path[$i - 1];

            // no such key!
            if (!isset($target[$subKey]) || ($i < $pathLength && !is_array($target[$subKey]))) {
                return false;
            }

            if ($i < $pathLength) {
                $target = &$target[$subKey];
            }
        }
        return true;
    }
239234
public function settingsKey($key)
    {
        if (is_array($this->settings) == false || isset($this->settings[$key]) == false) {
            return false;
        }

        return $this->settings[$key];
    }
1179362
public function has($key)
    {
        $keys = explode('.', $key);
        $cKeys = count($keys);
        $config = $this->_arr;

        for ($i = 0; $i < $cKeys; ++$i) {
            if (is_array($config)) {
                if (array_key_exists($keys[$i], $config)) {
                    $config = $config[$keys[$i]];
                } else {
                    return false;
                }
            } else {
                return false;
            }
        }

        return true;
    }
469164
public function has(string $key): bool
    {
        if (strpos($key, '.') != false) {
            return $this->getNested($key) != null;
        }

        return array_key_exists($key, $this->settings);
    }
1269953
public function get(string $key)
    {
        // 获取文件名称和位置
        list ($key, $path, $sqlPath) = $this->getFile($key);

        // 取目录
        $fileList = $this->getFileList();

        // 如果此数据不在缓存目录中
        if (!isset($fileList[$key])) {
            return self::getMiss($key);
        }

        // 取出当时缓存的有效期截止时间戳
        $expire = $fileList[$key];

        // 过期
        if ($expire < time()) {
            // 删除数据缓存文件
            unlink($path);
            unlink($sqlPath);

            // 从目录中去除
            unset($fileList[$key]);
            $this->setFileList($fileList);
            return self::getMiss($key);
        }

        if (!is_file($path)) {
            return self::getMiss($key);
        }

        // 取出缓存的数据
        $data = file_get_contents($path);
        return parent::debugGet($key, unserialize($data));
    }
162179
public function has($key): bool
    {
        return isset($this->items[$key]) || array_key_exists($key, $this->items);
    }
397443
public function hasConfigurationKey($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 $result;
    }
636374
public function has($key)
    {
        return (isset($this->headers[$this->normalizeKey($key)])) ? true : false;
    }
860114
public function delete(string $key): bool
    {
        $file = $this->cacheFile($key);

        if (is_file($file)) {
            return unlink($file);
        }

        return false;
    }
880129
public function delete(string $key): bool
    {
        /**
         * @var $handle \Memcache|\Memcached
         */
        $handle = $this->_handle;
        $ret = $handle->delete($key);
        Debug::setCache(static::$type, 'delete', $key, $ret);
        return $ret;
    }
1005396
protected function has($key)
    {
        if (!is_array($key)) {
            return (array_key_exists($key, $this->item));
        }

        foreach ($key as $value) {
            if (!array_key_exists($value, $this->item)) {
                return false;
            }
        }

        return true;
    }
233023
public function has( $key = null )
	{
		$keys = is_array( $key ) ? $key : func_get_args();

		foreach ( $keys as $key )
		{
			if ( $this->first( $key ) === '' )
			{
				return false;
			}
		}

		return true;
	}