vintasoft barcode .net sdk The Comparison Itself in Objective-C

Printer QR Code 2d barcode in Objective-C The Comparison Itself

The Comparison Itself
QR-Code Maker In Objective-C
Using Barcode creator for iPhone Control to generate, create QR-Code image in iPhone applications.
www.OnBarcode.com
Painting Code 3 Of 9 In Objective-C
Using Barcode generator for iPhone Control to generate, create USS Code 39 image in iPhone applications.
www.OnBarcode.com
The next two lines of code compare a couple of integers with areIntsDifferent() and store the return value into the areTheyDifferent variable. NSLog() prints out the numeric values and the human-readable string returned by boolString():
GS1 128 Creation In Objective-C
Using Barcode generation for iPhone Control to generate, create EAN 128 image in iPhone applications.
www.OnBarcode.com
Creating European Article Number 13 In Objective-C
Using Barcode generator for iPhone Control to generate, create EAN-13 Supplement 5 image in iPhone applications.
www.OnBarcode.com
areTheyDifferent = areIntsDifferent (5, 5); NSLog (@"are %d and %d different %@", 5, 5, boolString(areTheyDifferent));
Code128 Creator In Objective-C
Using Barcode printer for iPhone Control to generate, create Code128 image in iPhone applications.
www.OnBarcode.com
Encode QR-Code In Objective-C
Using Barcode drawer for iPhone Control to generate, create QR image in iPhone applications.
www.OnBarcode.com
As you saw earlier, NSLog() is basically a Cocoa-flavored printf() function that takes a format string and uses the additional parameters for values to plug in the format specifiers. You can see that the two fives will replace the two %d format placeholders in our call to NSLog(). At the end of the string we re giving to NSLog(), you see another at sign. This time, it s %@. What s that all about boolString() returns an NSString pointer. printf() has no idea how to work with an NSString, so there is no a format specifier we can use. The makers of NSLog() added the %@ format specifier to instruct NSLog() to take the appropriate argument, treat it as an NSString, use the characters from that string, and send it out to the console.
Paint Data Matrix In Objective-C
Using Barcode maker for iPhone Control to generate, create Data Matrix image in iPhone applications.
www.OnBarcode.com
Painting Universal Product Code Version E In Objective-C
Using Barcode encoder for iPhone Control to generate, create UPC-E Supplement 2 image in iPhone applications.
www.OnBarcode.com
CHAPTER 2: Extensions to C
Generate QR Code In None
Using Barcode generator for Software Control to generate, create Denso QR Bar Code image in Software applications.
www.OnBarcode.com
Encode Denso QR Bar Code In None
Using Barcode printer for Online Control to generate, create QR Code JIS X 0510 image in Online applications.
www.OnBarcode.com
NOTE
Making GS1-128 In Visual Studio .NET
Using Barcode encoder for .NET Control to generate, create EAN 128 image in VS .NET applications.
www.OnBarcode.com
PDF417 Maker In Visual Studio .NET
Using Barcode printer for Visual Studio .NET Control to generate, create PDF 417 image in .NET applications.
www.OnBarcode.com
We haven t officially introduced you to objects yet, but here s a sneak preview: when you print the values of arbitrary objects with NSLog(), you ll use the %@ format specification. When you use this specifier, the object supplies its own NSLog() format via a method named description. The description method for NSString simply prints the string s characters.
Code 128B Creation In None
Using Barcode generation for Software Control to generate, create Code 128C image in Software applications.
www.OnBarcode.com
Make Code128 In VS .NET
Using Barcode drawer for Reporting Service Control to generate, create Code 128 image in Reporting Service applications.
www.OnBarcode.com
The next two lines are very similar to those you just saw:
ECC200 Creation In None
Using Barcode creator for Online Control to generate, create Data Matrix ECC200 image in Online applications.
www.OnBarcode.com
Data Matrix ECC200 Recognizer In None
Using Barcode recognizer for Software Control to read, scan read, scan image in Software applications.
www.OnBarcode.com
areTheyDifferent = areIntsDifferent (23, 42); NSLog (@"are %d and %d different %@", 23, 42, boolString(areTheyDifferent));
Code 3 Of 9 Recognizer In Visual C#
Using Barcode recognizer for .NET Control to read, scan read, scan image in .NET framework applications.
www.OnBarcode.com
Generating Code39 In None
Using Barcode generation for Office Word Control to generate, create USS Code 39 image in Office Word applications.
www.OnBarcode.com
The function compares the values 23 and 42. This time, because they re different, areIntsDifferent() returns YES, and the user sees text stating the monumental fact that 23 and 42 are different values. Here s the final return statement, which wraps up our BOOL Party:
PDF417 Recognizer In None
Using Barcode recognizer for Software Control to read, scan read, scan image in Software applications.
www.OnBarcode.com
UCC - 12 Creator In None
Using Barcode generator for Online Control to generate, create GS1-128 image in Online applications.
www.OnBarcode.com
return (0); } // main
In this program, you saw Objective-C s BOOL type, and the constants YES and NO for indicating true and false values. You can use BOOL in the same way you use types such as int and float: as variables, parameters to functions, and return values from functions.
Summary
In this chapter, you wrote your first two Objective-C programs, and it was fun! You also met some of Objective-C s extensions to the language, such as #import, which tells the compiler to bring in header files and to do so only once. You learned about NSString literals, those strings preceded by an at sign, such as @"hello". You used the important and versatile NSLog(), a function Cocoa provides for writing text to the console, and the NSLog() special format specifier, %@, that lets you plug NSString values into NSLog() output. You also gained the secret knowledge that when you see an at sign in code, you know you re looking at an Objective-C extension to the C language. Stay tuned for our next chapter, in which we ll enter the mysterious world of object-oriented programming.
Introduction to Object-Oriented Programming
f you ve been using and programming computers for any length of time, you ve probably heard the term object-oriented programming more than once. Object-oriented programming, frequently shortened to its initials, OOP, is a programming technique originally developed for writing simulation programs. OOP soon caught on with developers of other kinds of software, such as those involving graphical user interfaces. Before long, OOP became a major industry buzzword. It promised to be the magical silver bullet that would make programming simple and joyous. Of course, nothing can live up to that kind of hype. Like most pursuits, OOP requires study and practice to gain proficiency, but it truly does make some kinds of programming tasks easier and, in some cases, even fun. In this book, we ll be talking about OOP a lot, mainly because Cocoa is based on OOP concepts, and Objective-C is a language that is designed to be object oriented. So what is OOP OOP is a way of constructing software composed of objects. Objects are like little machines living inside your computer and talking to each other in order to get work done. In this chapter, we ll look at some basic OOP concepts. After that, we ll examine the style of programming that leads to OOP, describing the motivation behind some OOP features. We ll wrap up with a thorough description of the mechanics of OOP.
Copyright © OnBarcode.com . All rights reserved.