Software Development Tutorials

Getting started guides, How-to's, and in-depth explanation of various topics in software development.

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Learn Objective-C: Floating-Point Operations

Objective-C Oct 2, 2010

Not all numbers are integers. Therefore, Objective-C lets you define floating-point values—numbers with a fractional portion. There are two basic types—float and double. Floating-point values do not follow the rules of integer division—that is, dividing by floating-point values produces

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Learn Objective-C: Integer Operations

Objective-C Sep 25, 2010

Extensions provide a more in-depth overview of various topics. Here, I present a more in-depth discussion behind primitive data types. Type int As mentioned before, integers consist of individual digits. You can prefix it with a minus sign (a hyphen) to make it negative. You cannot put spaces, commas,

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1

Objective-C Lesson 3: Object-Oriented Programming

Objective-C Sep 19, 2010

When object-oriented programming arrived in the programming world, it was considered a savior of software by some and yet another foolish experiment by others. Regardless of the perspective, we need to define some basic concepts and terminology before we begin. A Thing An object is a thing. In the

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Objective-C Lesson 2: Basic Variables

Objective-C Sep 14, 2010

In almost all programs, values may change; these values are stored in variables, which, as the name implies, are designed to have varying contents as the program is used. We’ll dive right in with a sample program. Program 2.1 // Introducing variables #import <Foundation/Foundation.h> int

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Learn Objective-C: Escape Sequences and Format Specifiers

Objective-C Sep 14, 2010

NSLog, and its corresponding C function printf(), use escape sequences to print certain characters that are “invisible.” For iOS, include: There are others, such as \a for Alert, but they are rarely used, and don’t make an effect. Format specifiers, however, are the percent character,

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Learn Objective-C: Reserved Keywords

Objective-C Sep 9, 2010

Objective-C reserves certain words, so that you can’t, or shouldn’t, use them in your own code. At best, you’ll get a compiler warning or error; at worst, you’ll get a nasty bug that you won’t discover until millions of people are already using your app. Here is a list of

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2

Learn Objective-C: A Brief History

Objective-C Sep 3, 2010

The Objective-C programming language has had a humble history. Created by Brad Cox in the early 1980s as an extension of the venerated C, pioneered a decade earlier by Dennis Ritchie, the language was based on another called SmallTalk-80. NeXT Software licensed the language in the 1988, and developed

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Learn Objective-C: Language Concepts

Objective-C Sep 3, 2010

C was conceived and created as a procedural programming language, whereas Objective-C was to be object-oriented, hence the name. In a procedural language, the code is focused around variables, data, and functions -- how to store data and what to do with the data. In contrast, an object-orientated language

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2

Back to Basics: How Programming Languages Work

Objective-C Sep 3, 2010

And now, a short diversion on the road to learning Objective-C. Warning: Extremely technical information follows. Feel free to skip this section for now, but make sure you do read it sometime. It’s important enough to know, but not vital for you to begin programming. A computer only understands

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Objective-C Lesson 1: Hello, World!

Objective-C Sep 3, 2010

Since Dennis Ritchie demoed the C programming language, it has been conventional to begin a programming course with a program that writes the words “Hello world!” to the computer screen. Diving right in, the code is shown below. Program 1.1 // First program example #import <Foundation/Foundation.h> int

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