MongoId
PHP Manual

MongoId::isValid

Check if a value is a valid ObjectId

Description

public static bool MongoId::isValid ( mixed $value )

This method may be used to check a variable before passing it as an argument to MongoId::__construct.

Parameters

value

The value to check for validity.

Return Values

Returns TRUE if value is a MongoId instance or a string consisting of exactly 24 hexadecimal characters; otherwise, FALSE is returned.