Objective-C is a combination of C and Small Talks
The trick is to understand the symbols and keywords
Understanding the Language Symbols
at the heart of Objective-C is C.
It's not important to know which are pure
{ his is the begin brace Blocks are used to defin and surround a section of code and define its scope.
- (void)methodName It represents what type of information the method represents.
* pointer
[] Thease are called brackets and are used when sending a message to an Objective-C object
@identify an Objective-C directive
#import
- (void)logMesage
{
NSString *hell = @"Hello World!";
NSLog(hello);
}
@ is an Objective-C directive and is a quick way of defining a constant string object
MSLog method
Objective is basis in Smalltalk
Pretty much everything is an object.
Objec
The @interface compiler directive
The identical object-oriented notion of inheritance works in Objective-C and many Cocoa touch classes.
remember the initial capital letter convention.
@interface NewSubclass : SuperClass
@symbol are called compiler directives.
tells the compiler that this section contains declarations of the variables and methods that will be fleshed out in the companion @implementation section .
a custom class needs far more infrastructure than what you'll be defining in the class files.
NSObject the most fundamental classs in the Foundation framework.
Foundation, UIKit and other frameworks inherit from NSObject
Using Xcode to Create DGCar Class Files
choose Cocoa Touch Class in the left column, then Objective-C class in the top right group
specify hat this will be a subclass of NSObject.
#import <Foundation/Foundation.h>
@intarface DGCar : NSObject {
}
@end