APPLE

*About Objective C?

Objective-C is a strict superset of the procedural-based C programming language. This
fact means that any valid C program is also a valid Objective-C program (albeit one
that doesn’t make use of any Objective-C enhancements).

*Differ from other?

Objective-C extends C by providing object-oriented features. The object-oriented
programming model is based on sending messages to objects, which is different
from the model used by C++ and Java, which call methods directly on an object. This
difference is subtle but is also one of the defining features that enables many of
Objective-C’s features that are typically more at home in a dynamic language such as
Ruby or Python.

*What is cocoa touch?

A programming language, however, is only as good as the features exposed by its
support libraries. Objective-C provides syntax for performing conditional logic and
looping constructs, but it doesn’t provide any inherent support for interacting with
the user, accessing network resources, or reading files. To facilitate this type of functionality
without requiring it to be written from scratch for each application, Apple
includes in the SDK a set of support libraries collectively called Cocoa Touch. If
you’re an existing Java or .NET developer, you can view the Cocoa Touch library as
performing a purpose similar to the Java Class Library or .NET’s Base Class Libraries
(BCL).

*Foundation and UIKIT

Cocoa Touch consists of a number of frameworks (commonly called kits). A framework
is a collection of classes that are grouped together by a common purpose or task.
The two main frameworks you use in iPhone applications are Foundation Kit and
UIKit. Foundation Kit is a collection of nongraphical system classes consisting of data
structures, networking, file IO, date, time, and string-handling functions, and UIKit is
a framework designed to help develop GUIs with rich animations.

*Iphone 4 Screen Resolution

On taking an initial look at an iPhone 4, you’ll undoubtedly notice the 3.5-inch
screen, 960 x 640 pixels, that virtually dominates the entire front of the device. Its general
size and the fact that the built-in touch screen is the only way for users to interact
with the device can have important ramifications on application design. Although 960
x 640 is larger than many cell phones, it probably isn’t the screen on which to view a
300-column-by-900-row spreadsheet.