iPhone SDK Objective-C Cheat Sheet Updated

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I have updated the Cheat Sheet on this site with larger headers as suggested by visitors to the site. For those that don’t know this is a cheat sheet designed for beginners just getting started with the iPhone SDK who have some knowledge of C/C++ or Java providing comparisons with similar syntax in those languages for common Objective-C keywords.

Covered is:
Messages
Import
Self
Method Headers
Inheritance
Property and Synthesize
Interface
Implementation
Protocol
Id

You can find the cheatsheet here:
>>> iPhone Objective-C Cheat Sheet <<<

This is the original video I made explaining the concepts contained within this cheatsheet:

Here is a little video I made about this cheatsheet update:

Please post any suggestions for improvement in the comments.
Thanks.

Getting started with iPhone and iPad development, and looking for a straightforward guide to get you started with Objective-C fast as possible?
Click here to check out a great straightforward no-nonsense guide to getting started with iPhone development as fast as possible.

Share and Enjoy:

BrooksR

Very nice. Would you do one for VB developers?
mxweas

Add categories?
ie:
@interface NSString (MyCoolAddition)
- (NSString *)shuffleString;
@end

@implementation NSString (MyCoolAddition)
- (NSString *)shuffleString {
//Do some shuffling here
//Return shuffled string
}
@end
TomG

Why aregue about these semantics?

The terms class method and static method are basically interchangeable, just check wikipedia, or check numerous books.

http://en.wikipedia.org/wiki/Method_(computer_s...)

Yes, class methods are dynamically dispatched, but they're just like C++ static methods as the poster said. It's just semantics that won't matter to someone who is brand new to the language and needing a cheat sheet.
maniacdev

Thanks for everyone's comments and am going to implement as much as I can into the cheat sheet..

Keep in mind, I originally created this cheat sheet for people just transitioning from C/C++/Java to Obj-C for the first time so that they could begin to understand the code.

My plan is to create another cheat sheet with more intermediate concepts specifically to coincide with the second app that we'll be creating in my video tutorials. Before a more advanced cheat sheet prior to getting into apps using OpenGL ES.

Stay tuned, and I appreciate all the suggestions so keep them coming.
David Maymudes

one suggestion: how about something about using "+" instead of the leading "-" to indicate a static method... it's the kind of thing that's impossible to Google to find out, and I'm sure there are lots of people new to Objective C who are asking themselves "why does everything have a leading dash?"
Chris Hanson

A leading + doesn't indicate a static method, it indicates a class method. The difference is that class methods are dynamically dispatched just like instance methods, and can be overridden in subclasses just like instance methods.
David Maymudes

That's exactly my point--I had no idea what it's called, so that would be a great thing for the cheat sheet because you can't Google "objective C plus minus" to find out what it means. I was saying that it's like a C++ static method in the sense that it doesn't operate on a specific instance of a class.

(Hey, you know what--I just assumed that that Google search wouldn't work. If you actually do the search, the first result is the Wikipedia Objective C page with an explanation of what + and - mean. Google, I will never doubt you again.)
maniacdev

I see what you're getting at Chris.. your comment was originally morphed in my WP-Admin and I wondered wth you were talking about.. I'll add a little bit to that section to make it clear that you are not accessing the variables directly.
TomG

LOL, it doesn't matter maniac, no one is going to get confused like that.
Chris Hanson

The cheat sheet refers to "@property dataType variableName" and "@synthesize variableName". That's incorrect; properties are not the same thing as instance variables. A property may use an instance variable for storage, but it isn't one itself. That's part of why people are confused by the difference between referring to just "foo" in their class and referring to "self.foo" - people tell them properties are a way of declaring accessors for instance variables, not that they're a way of declaring methods that may access an instance variable.

ManiacDev.Com

iPhone SDK Objective-C Cheat Sheet Updated

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