Can I determine if a string is a MongoDB ObjectID?

Question

I am doing MongoDB lookups by converting a string to BSON. Is there a way for me to determine if the string I have is a valid ObjectID for Mongo before doing the conversion?

Answer 1

Warning: isValid will return true for arbitrary 12/24 length strings beginning with a valid hex digit. Currently I think this is a better check:

((thing.length === 24 || thing.length === 12) && isNaN(parseInt(thing,16)) !== true)