Data Types

Objective-C	C#
int	int
unsigned	uint
float	float
double	double
char	char
BOOL	bool
NSString	string
id	object

Objective-C to C#

This is my personal reference to help me learn Objective-C. The example Ojective-C code is taken from Scott Stevenson's Learn Objective-C. It's a great tutorial. Use this reference to help understand the difference (likeness) between Objective-C and C#.

Objective-C	C#
Message	Method
Calling Methods
[object method];	object.Method();
[object methodWithInput:input];	object.MethodWithInput(input);
output = [object methodWithOutput];	output = object.Method();
id myObject = [NSString string];	object myObject = new StringBuilder();
NSString* myString = [NSString string];	StringBuilder myString = new StringBuilder(); It's really: string myString;
Nested Messages
[NSString stringWithFormat:[prefs format]];	NSString.StringWithFormat(prefs.format());
Multi-Input Methods
-(BOOL)writeToFile:(NSString*)path atomically:(BOOL)useAuxiliaryFile;	/// <param name="useAuxiliaryFile">atomically</param> bool WriteToFile(string path, bool useAuxiliaryFile);
BOOL result = [myData writeToFile:@"/tmp/log.txt" atomically:NO];	bool result = myData.WriteToFile(@"/tmp/log.txt", false);
Accessors
photo.caption = @"Day at the Beach"; output = photo.caption;	photo.Caption = "Day at the Beach"; output = photo.Caption;
Creating Objects
NSString* myString = [NSString string];	StringBuilder myString = new StringBuilder();
NSString* myString = [[NSString alloc] init];	StringBuilder myString = new StringBuilder();
NSNumber* value = [[NSNumber alloc] initWithFloat:1.0];	float value = 1.0;
Designing a Class Interface
Photo.h	Photo.cs
#import <Cocoa/Cocoa.h> @interface Photo : NSObject {     NSString* caption;     NSString* photographer; } @property (retain) NSString* caption; @property (retain) NSString* photographer; @end	interface IPhoto : INSObject {     string Caption { get; set; }     string Photographer { get; set; } }
Class Implementation
#import "Photo.h" @implementation Photo @synthesize caption; @synthesize photographer; - (void) dealloc {     self.caption = nil;     self.photographer = nil;     [super dealloc]; }   @end	class Photo : IPhoto {     public string Caption { get; set; }     public string Photographer { get; set; } }

Learning Objective-C

This second tutorial should be your next step to learning Objective-C. My plan is to provide C# examples that go along with these tutorials. Perhaps I can get permission from the author, Scott Stevenson, to republish his work on this blog with C# examples and commentary.

Step 1: Introduction to Objective-C

Here is a great resource to learning the very basics of C. This is recommended as your first step.