I developed one website in google maps api V2, now management is saying V2 is deprecated and convert in to V3. While googling the V3 i didn’t see any api key? then how it works?

http://maps.googleapis.com/maps/api/js?sensor=false

src="http://maps.google.com/maps?file=api&v=2&sensor=false&key=ABQIAAAAZIdFD1WVdDZkZtynpOarChQNeNa5CKtG0-vmTH0qjucdvCYnQxSdAQEaIYCVLr1JYZPtbiF0LjTojQ"

and how to convert from V2 to V3? should i develop it from scratch onwards?

Google maps api v3 doesn’t need a key like v2. You are encouraged to use v3 because of the support for devices like iphone and android.

Googe maps api v3 has been implemented using modified MVC framework. .

Any state changes of an MVC object (such as a map) for example, are
handled through setters and getters of a particular format. As well,
all state of the MVC objects are stored as properties of that object,
and all observation of state changes through event handlers is of a
particular format as well.

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google-maps,google-maps-api-3,javascript