1. methods
   1. instance method
      1. the actions performed on the instance
         1. eg
            1. setting value
            2. retrieving value
            3. printing value
   2. class method
      1. applies to a class
         1. eg
            1. creating a new instance of a class
   3. Subtopic 3
   4. applying method can affect state of object
   5. can apply same methods to different objects
      1. a key concept
   6. syntax
      1. ( ClassOrInstance method );
         1. 1st... left bracket
         2. 2nd... name of class or instance
         3. 3rd.... a space
         4. 4th... name of method
         5. 5th... closed off with right bracket
         6. 6th... semicolon to teminate
      2. ( receiver message );
         1. different way to think about syntax format
         2. ask to perform some action = sending "message" to class/instance
         3. recipient is "reciever"
            1. class or method
         4. method is the message
   7. example of applying a class method
      1. send message to Car class (reciever)
      2. asking to give new car
      3. resulting object is stored in variable yourCar
      4. class or factory method
   8. example of instance method
      1. actions on new car are instance methods
   9. minus sign (-) is instance method
   10. plus sign (+) is class method
2. object
   1. thing
   2. something that I want to do to a thing
   3. instance of a class
   4. each instance is an object
   5. each object has unique characteristics
   6. instance variable
   7. has own set of instance variables
3. class car
   1. object myCar
      1. method drive it
      2. method fill with gas
      3. method wash it
      4. method service it
4. create new class and object (3.2)
   1. @interface section
      1. does 3 things
         1. describes class
         2. describes class data components
         3. describes class methods
         4. Summary
      2. to define a class - 3 things
         1. tell compiler what "parent" class new class came from
         2. specify data to be stored in objects of class
         3. define type of operations (methods) that can be used with objects
         4. Summary
      3. @interface section general format
      4. @interface example 3.2
         1. what is this section called????????????
            1. new class name Fraction
            2. parent class NSObject
            3. NSObject class defined in NSObject.h
            4. NSObject.h included when import Foundation.h
         2. memberDeclaration section
            1. members declared are "instance variables"
            2. specifies type of data stored in new class
            3. specifies names of data types
            4. closed in curly braces
            5. this example has two "integer members" called numerator and denominator
         3. Subtopic 4
            1. displays value of the declared members
            2. minus sign (-) means it's an instance method
         4. Subtopic 3
   2. @implementation section
      1. contains the code that implements class methods
   3. program section
      1. contains program code
5. forming variable names
   1. 1. begin with letter or underscore
   2. 2. follow with letters, underscores, digits
   3. "reserved words/name" not used
      1. Appendix B for list
   4. cannot start with number
   5. no spaces
   6. no invalid characters
   7. upper/lower case sensitive
   8. classes start with upper-case (by convention)
      1. "AddressBook"
   9. instance variables/objects start with lower-case
      1. "currentEntry" or "current_entry"
   10. methods start with lower-case
       1. "addNewEntry"
   11. upper-case inside names to start new word
       1. readability
   12. pick meaningful names
       1. increase readability
       2. good for debug/documentation phases
       3. program more self-explanatory