学习Objective-C。目标C是一个通用的，面向对象的程序设计
Learn Objective-C
Objective-C is a general-purpose, object-oriented programming language that adds Smalltalk-style messaging to the C programming language. This is the main programming language used by Apple for the OS X and iOS operating systems and their respective APIs, Cocoa and Cocoa Touch.
This reference will take you through simple and practical approach while learning Objective-C Programming language.
This reference has been prepared for the beginners to help them understand the basic to advanced concepts related to Objective-C Programming languages.