How can I identify the particular iOS device is an iPhone 3G or an iPhone 4?

How can I identify if the iOS device my开发者_如何转开发 app runs on is an iPhone 3G of an iPhone 4?

Thanks in advance.

Check out uidevice-extension by Erica Sadon.

You can use the following:

[[UIDevice currentDevice] platformType];
[[UIDevice currentDevice] platformString];