Checks if a key exists.

@param  string|array $key Key name or an array keys.
@return bool
770565
public function exists( $key ) {
		return ! collect( is_array( $key ) ? $key : func_get_args() )->contains(
			function ( $key ) {
				return ! Arr::exists( $this->attributes, $key );
			}
		);
	}
1259685
public function has($key): bool
    {
        return ArrayUtility::dotRead($this->data, $this->getNormalizedKey($key)) !== null;
    }
684459
public function exists($key) {
		return isset($this->_data[$key]) || isset($this->registered[$key]);
	}
720766
public function has($key)
    {
        // For performance, we can use isset,
        // but it will not match if value == 0
        return isset($this->values[$key]) || array_key_exists($key, $this->values);
    }
566699
public function hasKey(string $key): bool
    {
        return $key && strpos($key, '@@') === false && file_exists($this->getPathFromKey($key));
    }
1088173
public function has($key)
    {
        $keys = (func_num_args() > 1) ? func_get_args() : (array) $key;

        foreach ($keys as $key) {
            if(!array_key_exists($key, $_SESSION))
                return false;
        }

        return true;
    }
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);
        }
    }
972886
public function ifExists(string $key): bool
    {
        if ($this->get($key) === false) {
            return false;
        }

        return true;
    }
521394
public function contains($key)
    {
        return isset($this->_data[$key]) || array_key_exists($key, $this->_data);
    }
1041803
public function has($key)
    {
        $keys = (func_num_args() > 1) ? func_get_args() : (array) $key;

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

        return true;
    }
856790
public function has(string $key): bool
    {
        if (array_key_exists($key, $this->ttl) &&
            $this->time() - $this->ttl[$key] > 0
        ) {
            unset($this->ttl[$key]);
            unset($this->storage[$key]);

            return false;
        }

        return array_key_exists($key, $this->storage);
    }
1339046
public function hasQuery($key)
    {
        $arrayKeys = array_keys($_GET);
        $keys = is_array($key) ? $key : func_get_args();

        foreach ($keys as $value) {
            if (!in_array($value, $arrayKeys) || trim((string)$_GET[$value]) === '') {
                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, $this->settings);
    }
278793
public function has($key)
	{
		$key = $this->id($key);
		return $this->apcu ? apcu_exists($key) : apc_exists($key);
	}
863025
public function has($key): bool
    {
        $key = $this->getKeyword($key)->getSlug();

        return ! empty($key) && \in_array($key, $this->items);
    }
578242
public function exists($key) {

		if(false === is_string($key) && false === is_array($key)) {
   			return trigger_error(sprintf('Argument 1 passed to %s() must be of the type string or array, "%s" given', __METHOD__, gettype($key)), E_USER_ERROR);
   		}

   		if(0 === strlen($key)) {
   			return trigger_error(sprintf('Argument 1 passed to %s() may not be an empty string', __METHOD__), E_USER_ERROR);
   		}

		return apcu_exists($key);
	}
113950
public function exists($key) {
        $key = $this->secureKey($key);
        
        if (isset($_SESSION[$key])) return true;
        
        return false;
    }