iOS100
iOS Platform Development Introduction
Day 4
Last time in iOS100...
We further explored:
-
Objective-C Review
- Objects
- Using Instances
- Creating Objects
- Sending Messages
RandomItems
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Created a command line tool
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Created and populate arrays with objects
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Iterated though our arrays
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Subclassed an Objective-C class (NSObject)
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Overrode parent class methods
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Implemented out own custom Initializers
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Implement class and instance methods
- Implemented properties for our instance varables
Quiz
What is the difference between the following two method calls?
// Create a variable that will point to an NSMutableArray Object... NSMutableArray *myParty;
myParty = [NSMutableArray alloc];
VS
?
Class vs Instance Methods
- Instance Methods
- Operates on a particular instance of a class
- Invoked by sending a message to a specific instance of a class
- Denoted by a "-" in the method declaration
- Class Methods
- Typically creates a new instance of the class or retrieves a global property of the class.
- Invoked by sending a message to the class itself
- Denoted by a "+" in the method declaration
Quiz
What are two different ways we can iterate though an array?
Practice
-
Create a mutable party array object that contains the following:
- Output all of the values inside of the array
- Manually
- Traditional for loop
- Fast enumeration
Quiz
What is overriding a method?
Practice
Override the description method of a class to return the string
"I control you!"
Todays Agenda
- Create a prime number calculator
- Building user interfaces
- Simple Controls
- Interacting with controls from a class
- Error handling