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Matthew Alexander
Matthew Alexander
14,000 Points


Could you explain to me the jargon in iOS Development.


  1. Class
  2. Instance Methods
  3. Instance Variables
  4. Self
  5. Object
  6. Instance
  7. Frames
  8. Interface
  9. Implementation


2 Answers

Matthew Mascioni
Matthew Mascioni
20,444 Points


There's a great Class explanation provided by Apple.

Instance Method

An instance method is a method on the instance of a class. For example, NSArray's count method is an instance method because it works on an instance of an NSArray object.

Instance Variables

This is useful for instance variables.


self is a keyword used as a reference to an object executing a method. For example, in the Crystal Ball app, we see the following line of code:


This indicates that predictionLabel is a property of our THViewController class.


In Objective-C, objects are a big thing. They represent instances of a class. For example, in this line of code:

NSString *string = @"Hi Treehouse!";

I've created an instance of an object, of the class NSString, then setting it to the value "Hi Treehouse!". This is discussed in detail in Objective-C Basics.


This is a great explanation on instances.


Frames represent a rectangular area on the device's screen, and are fundamental in iOS programming.


The @interface is where you declare your properties, class and instance methods, among other things.


Implementation is the actual implementation of the methods we've declared in our @interface.

These were all very rough explanations: however, Treehouse's iOS development track will teach these things in much greater detail. I suggest you start out with Objective-C Basics and test the waters to see if it's something you'd like :)

Matthew Alexander
Matthew Alexander
14,000 Points

Thanks so much, by the way I have finished Objective-C basics so I was just reviewing my terms.