# SessionUpdateTimestampHandlerInterface::validateId

(PHP 7)

SessionUpdateTimestampHandlerInterface::validateId — Validate ID

### Description

abstract public SessionUpdateTimestampHandlerInterface::validateId ( string `$key` ) : bool

Validates a given session ID. A session ID is valid, if a session with that ID already exists. This function is automatically executed when a session is to be started, a session ID is supplied and session.use_strict_mode is enabled.

### Parameters

`key`

  The session ID.

### Return Values

Returns `TRUE` for valid ID, `FALSE` otherwise. Note that this value is returned internally to PHP for processing.