Onstorage Event

Hello,

I understand that onstorage event will be invoked if setItem, removeItem or
clear is invoked on either sessionStorage object or localStorage object. I
am curious how can I determine which object has changed from within the
onstorage event handler. To be precise, is the function called because
localStorage object changed or sessionStorage object changed. storageArea
attribute to event object does not help. If this is not possible, I am
curious what is the reason behind not to support this ? I can imagine user
wants to do different thing based on if localStorage changed or
sessionStorage changed.

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Thanks,
Jaikishan