learnxinyminutes-docs/objvectiv-C.html.markdown

language	author	author_url	filename
Objectiv-C	Eugene Yagrushkin	www.about.me/yagrushkin	learnc.Objectiv-C

Objective-C is the main programming language used by Apple for the OS X and iOS operating systems and their respective APIs, Cocoa and Cocoa Touch. It's is a general-purpose, object-oriented programming language that adds Smalltalk-style messaging to the C programming language.

// Single-line comments start with //

/*
Multi-line comments look like this.
*/

// Import headers with #import
#import <UIKit/UIKit.h>
#import "SomeAppDelegate.h"

// Declare your class in a header(.h) file:

@interface UserObject : NSObject{
// instance variables
}

// Class method
	+ (NSString*) ClassMethod;

// Instance method
	- (NSString*) instanceMethodWithParmeter:(NSString*)string;

@end

// Add class methods in an implementation (.m) file:

@implementation UserObject

+ (NSString*) ClassMethod{
	return @"SomeString";
}

- (NSString*) instanceMethodWithParmeter:(NSString*)string;
{
	return [NSString stringWithString:string];
}

@end

// Create an object instance by allocating memory and initializing it. An object is not fully functional until both steps have been completed.
UserObject *someObject = [[UserObject alloc] init];

// The Objective-C model of object-oriented programming is based on message passing to object instances. 
// In Objective-C one does not simply call a method; one sends a message.

[someObject instanceMethodWithParmeter@"Steve Jobs"];

Further Reading

Wikipedia Objective-C

Objectively Speaking: A Crash Course in Objective-C

iOS For High School Students: Getting Started