iOS Deployment Target & Block Support

If I use blocks in my code and set the iOS Deployment Target to less than iOS 4.0, will the app still work 开发者_如何学Pythonon devices that are running an iOS less than 4.0?

The Base SDK is set to Latest iOS (iOS 4.3) obviously.

From the apple documentation:

Blocks are available in GCC and Clang as shipped with the Mac OS X v10.6 Xcode developer tools. You can use blocks with Mac OS X v10.6 and later, and iOS 4.0 and later.

So the answer is no, you can't use blocks when deploying to 3.2 targets.