About Objective- CObjective- C is the primary programming language you use when writing software for OS X and i. OS. Objective- C inherits the syntax, primitive types, and flow control statements of C and adds syntax for defining classes and methods. It also adds language- level support for object graph management and object literals while providing dynamic typing and binding, deferring many responsibilities until runtime. At a Glance. This document introduces the Objective- C language and offers extensive examples of its use. Although the framework classes are separate from the language, their use is tightly wound into coding with Objective- C and many language- level features rely on behavior offered by these classes. Objective-c tutorial Objective-C is a general-purpose. Cocoa and Cocoa Touch. Notice the SEL type, which is the type of messages in Objective-C. Note: in OpenStep, Cocoa. All Objective-C applications developed for Mac OS X that make use of the above. You'll learn how to work with the Xcode IDE, Objective-C's Foundation. Easy to carry and easy to useālets you ditch all those bulky books for one portable. Objective-C For Dummies will teach you what you need to know. An App Is Built from a Network of Objects. When building apps for OS X or i. OS, you. Those objects are instances of Objective- C classes, some of which are provided for you by Cocoa or Cocoa Touch and some of which you. This interface includes the public properties to encapsulate relevant data, along with a list of methods. Method declarations indicate the messages that an object can receive, and include information about the parameters required whenever the method is called. You can use a category to add methods to any class, including classes for which you don. Class extensions are commonly used to hide private behavior for use either within a single source code file, or within the private implementation of a custom framework. Protocols Define Messaging Contracts. The majority of work in an Objective- C app occurs as a result of objects sending messages to each other. Often, these messages are defined by the methods declared explicitly in a class interface. Sometimes, however, it is useful to be able to define a set of related methods that aren. Any class can indicate that it adopts a protocol, which means that it must also provide implementations for all of the required methods in the protocol. Values and Collections Are Often Represented as Objective- C Objects. It. The NSString class is used for strings of characters, the NSNumber class for different types of numbers such as integer or floating point, and the NSValue class for other values such as C structures. Read Book PDF Online Here http:// MacBook All-in-One For Dummies Now.Download C All In One For Dummies PDF eBook C All In One For Dummies C ALL IN ONE FOR DUMMIES EBOOK AUTHOR BY JOHN PAUL. Read Online and Download Ebook Objective C Cocoa And Xcode All In One For Dummies. It is also possible to write Objective-C Cocoa programs in a simple text editor and build it manually with GNU Compiler. Objective-C; Xcode; iOS SDK; Interface Builder. Cocoa Programming for Dummies, 1st Edition 2003. You can also use any of the primitive types defined by the C language, such as int, float or char. Collections are usually represented as instances of one of the collection classes, such as NSArray, NSSet, or NSDictionary, which are each used to collect other Objective- C objects. Blocks Simplify Common Tasks. Blocks are a language feature introduced to C, Objective- C and C++ to represent a unit of work; they encapsulate a block of code along with captured state, which makes them similar to closures in other programming languages. Blocks are often used to simplify common tasks such as collection enumeration, sorting and testing. They also make it easy to schedule tasks for concurrent or asynchronous execution using technologies like Grand Central Dispatch (GCD). Error Objects Are Used for Runtime Problems. Although Objective- C includes syntax for exception handling, Cocoa and Cocoa Touch use exceptions only for programming errors (such as out of bounds array access), which should be fixed before an app is shipped. All other errors. Your app should plan for errors and decide how best to handle them in order to present the best possible user experience when something goes wrong. Objective- C Code Follows Established Conventions. When writing Objective- C code, you should keep in mind a number of established coding conventions. Method names, for example, start with a lowercase letter and use camel case for multiple words; for example, do. Something or do. Something. Else. Property accessor methods, for example, must follow strict naming conventions in order to work with technologies like Key- Value Coding (KVC) or Key- Value Observing (KVO). Prerequisites. If you are new to OS X or i. OS development, you should read through Start Developing i. OS Apps Today or Start Developing Mac Apps Today before reading this document, to get a general overview of the application development process for i. OS and OS X. Additionally, you should become familiar with Xcode before trying to follow the exercises at the end of most chapters in this document. Xcode is the IDE used to build apps for i. OS and OS X; you. If you have knowledge of another higher- level programming language, such as Ruby or Python, you should be able to follow the content. Reasonable coverage is given to general object- oriented programming principles, particularly as they apply in the context of Objective- C, but it is assumed that you have at least a minimal familiarity with basic object- oriented concepts. For more information about Xcode, see Xcode Overview. For information on language feature availability, see Objective- C Feature Availability Index. Objective- C apps use reference counting to determine the lifetime of objects. For the most part, the Automatic Reference Counting (ARC) feature of the compiler takes care of this for you. If you are unable to take advantage of ARC, or need to convert or maintain legacy code that manages an object.
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