The document provides an overview of various Objective-C concepts including classes, objects, methods, properties, protocols, categories, dictionaries, property lists, user defaults, errors, delegates, callbacks, and table views. It discusses core classes like NSString, NSArray, NSDictionary, and NSMutableDictionary. It covers concepts like inheritance, polymorphism, and memory management using retain, release, and autorelease. The document also provides examples of declaring and defining classes, creating class instances, and implementing table views with custom cells.
Implementation details and performance traits of generics in .NET, Java and C++. Presentation for the Jerusalem .NET/C++ User Group by Sasha Goldshtein.
ppt of class and methods in java,recursion in java,nested class,java,command line argument,method overloading,call by value,call by reference,constructor overloading core java ppt
Implementation details and performance traits of generics in .NET, Java and C++. Presentation for the Jerusalem .NET/C++ User Group by Sasha Goldshtein.
ppt of class and methods in java,recursion in java,nested class,java,command line argument,method overloading,call by value,call by reference,constructor overloading core java ppt
Programming with Segue
Dynamic design through coding
Views and its Co-ordinates
Core animations
Picture pickers
Sound manager
Address book picker
- Hussain KMR Behestee
My talk at BarCamp London 5: An introduction to Cocoa development and how web developers can cheat.
Source code to go with this presentation is available here: http://georgebrock.com/conferences/barcamplondon5
Contents :
Language Concepts
How Objective C works- Basics
Data Types
NSInteger
NSNumber
Operators
Loop
Inheritance
Method Overloading
Mutable and Immutable Strings
Mutable and Immutable Arrays
File Management
Object Trampoline: Why having not the object you want is what you need.Workhorse Computing
Overview of Trampoline Objects in Perl with examples for lazy construction, lazy module use, added sanity checks. This version includes corrections from the original presented at OSCON 2013 and comments.
iOS development Crash course in how to build an native application for iPhone.
i will be start from beginning till publishing on Apple Store step by step.
this session # 1 after the intro
Node.js allows you to run JavaScript code outside of a browser window, offering powerful tools to interact with a computer filesystem, run web servers, and create terminal applications. Node handles these tasks by running asynchronously, which means that reading user input from a terminal isn’t as simple as calling a getInput() function. In this article, we’ll show you an easy way around that (and some tips and tricks for handling user input) by using a helpful Node module.
readline-sync: This is the third party module that is used for taking the input from the user synchronously. So, the execution of the programs is line by line.
Installing module:
npm install readline-sync
Instructions for Submissions thorugh G- Classroom.pptxJheel Barad
This presentation provides a briefing on how to upload submissions and documents in Google Classroom. It was prepared as part of an orientation for new Sainik School in-service teacher trainees. As a training officer, my goal is to ensure that you are comfortable and proficient with this essential tool for managing assignments and fostering student engagement.
How to Create Map Views in the Odoo 17 ERPCeline George
The map views are useful for providing a geographical representation of data. They allow users to visualize and analyze the data in a more intuitive manner.
Operation “Blue Star” is the only event in the history of Independent India where the state went into war with its own people. Even after about 40 years it is not clear if it was culmination of states anger over people of the region, a political game of power or start of dictatorial chapter in the democratic setup.
The people of Punjab felt alienated from main stream due to denial of their just demands during a long democratic struggle since independence. As it happen all over the word, it led to militant struggle with great loss of lives of military, police and civilian personnel. Killing of Indira Gandhi and massacre of innocent Sikhs in Delhi and other India cities was also associated with this movement.
How to Make a Field invisible in Odoo 17Celine George
It is possible to hide or invisible some fields in odoo. Commonly using “invisible” attribute in the field definition to invisible the fields. This slide will show how to make a field invisible in odoo 17.
Welcome to TechSoup New Member Orientation and Q&A (May 2024).pdfTechSoup
In this webinar you will learn how your organization can access TechSoup's wide variety of product discount and donation programs. From hardware to software, we'll give you a tour of the tools available to help your nonprofit with productivity, collaboration, financial management, donor tracking, security, and more.
4. Classes from Apple (and some history)
NSString is a string of text that is immutable.
NSMutableString is a string of text that is mutable.
NSArray is an array of objects that is immutable.
NSMutableArray is an array of objects that is
mutable.
NSNumber holds a numeric value.
5. Objective-C Characteristics and
Symbols
Written differently from other languages
Object communicate with messages—does not “call” a
method.
@ indicates a compiler directive. Objective-C has own
preprocessor that processes @ directives.
# indicates a preprocessor directive. Processes any #
before it compiles.
6. Declare in Header file (.h)
Each method will start with either a – or a + symbol.
- indicates an instance method (the receiver is an
instance)
+indicates a class method (the receiver is a class name)
Example of a instance method
-(IBAction)buttonPressed:(id)sender;
Or with one argument
-(void)setFillColor:(NSColor*) newFillColor;
7. Parts of a Method in a Class
Implement the method in the .m file
Example:
-(IBAction)buttonPressed:(id)sender{
do code here….
}
Example 2:
-(void) setOutlineColor:(NSColor*) outlineColor{
do code here….
}
8. Class Declaration (Interface)
Node.h
#import <Cocoa/Cocoa.h>
@interface Node : NSObject {
Node *link;
int contents;
Class is Node who’s parent is
} NSObject
+(id)new;
{ class variables }
-(void)setContent:(int)number;
-(void)setLink:(Node*)next;
-(int)getContent; +/- private/public methods of Class
-(Node*)getLink;
@end
Class variables are private
9. Class Definition (Implementation)
#import “Node.h”
@implementation Node Node.m
+(id)new
{ return [Node alloc];}
-(void)setContent:(int)number
{contents = number;}
-(void)setLink:(Node*)next {
[link autorelease];
link = [next retain]; Like your C++ .cpp
} file
-(int)getContent
{return contents;}
-(Node*)getLink >>just give the
{return link;} methods here
@end
10. Creating class instances
Creating an Object
ClassName *object = [[ClassName alloc] init];
ClassName *object = [[ClassName alloc] initWith* ];
NSString* myString = [[NSString alloc] init];
Nested method call. The first is the alloc method called on NSString itself.
This is a relatively low-level call which reserves memory and instantiates an
object. The second is a call to init on the new object. The init implementation
usually does basic setup, such as creating instance variables. The details of
that are unknown to you as a client of the class. In some cases, you may use a
different version of init which takes input:
ClassName *object = [ClassName method_to_create];
NSString* myString = [NSString string];
Some classes may define a special method that will in essence call alloc followed by some
kind of init
11. Reference [[Person alloc] init];action
Person *person =
counting in
Retain count begins at 1 with +alloc
[person retain];
Retain count increases to 2 with -retain
[person release];
Retain count decreases to 1 with -release
[person release];
Retain count decreases to 0, -dealloc automatically
called
12. Autorelease
Example: returning a newly created object
-(NSString *)fullName
{
NSString *result;
result = [[NSString alloc] initWithFormat:@“%@
%@”, firstName, lastName];
[result autorelease]
return result;
}
13. Method Names & Autorelease
Methods whose names includes alloc, copy, or new return a retained
object that the caller needs to release
NSMutableString *string = [[NSMutableString alloc] init];
// We are responsible for calling -release or -autorelease
[string autorelease];
All other methods return autoreleased objects
NSMutableString *string = [NSMutableString string];
// The method name doesn’t indicate that we need to release
it, so don’t
This is a convention- follow it in methods you define!
14. Polymorphism
Just as the fields of a C structure are in a protected
namespace, so are an object’s instance variables.
Method names are also protected. Unlike the names of
C functions, method names aren’t global symbols. The
name of a method in one class can’t conflict with
method names in other classes; two very different
classes can implement identically named methods.
Objective-C implements polymorphism of method
names, but not parameter or operator overloading.
23. We will see this in
Property list (plist) practice later
A collection of collections
Specifically, it is any graph of objects containing only the following classes:
NSArray, NSDictionary, NSNumber, NSString, NSDate, NSData
Example1 : NSArray is a Property List if all its members are too
NSArray of NSString is a Property List
NSArray of NSArray as long as those NSArray’s members are Property Lists.
Example 2: NSDictionary is one only if all keys and values are too
Why define this term?
Because the SDK has a number of methods which operate on Property Lists.
Usually to read them from somewhere or write them out to somewhere.
[plist writeToFile:(NSString *)path atomically:(BOOL)]; // plist is NSArray or
NSDictionary
24. NSUserDefaults
Lightweight storage of Property Lists.
an NSDictionary that persists between launches of
your application.
Not a full-on database, so only store small things like
user preferences.
25. Use NSError for Most Errors
No network connectivity
The remote web service may be inaccessible
The remote web service may not be able to serve the
information you request
The data you receive may not match what you were
expecting