How to access API reference from Xcode?

I'm tired of switching between xcode and the browser to check iPhone API reference from Apple web site. Any better way to to it directly from Xcode ? Ideally I'd like to select a word and search for it开发者_如何转开发 in the APi reference automatically.

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There is a copy of the API reference in your local machine already. Check Help -> Developer Documentation.

You can also use "Opt + Double click" on a word to get quick help, "Cmd + Opt + Double click" to get detailed doc.