Referring to Other Classes 36
The Role of the Interface 37
Class Implementation 37
Referring to Instance Variables 39
The Scope of Instance Variables 40
Messages to self and super 43
An Example: Using self and super 45
Using super 47
Redefining self 47
Protocols 50
Declaring Interfaces for Others to Implement 50
Methods for Others to Implement 51
Declaring Interfaces for Anonymous Objects 52
Nonhierarchical Similarities 53
Formal Protocols 54
Declaring a Protocol 54
Optional Protocol Methods 54
Informal Protocols 55
Protocol Objects 56
Adopting a Protocol 57
Conforming to a Protocol 57
Type Checking 58
Protocols Within Protocols 59
Referring to Other Protocols 60
Declared Properties 62
Overview 62
Property Declaration and Implementation 62
Property Declaration 63
Property Declaration Attributes 64
Property Implementation Directives 67
Using Properties 69
Supported Types 69
Property Redeclaration 69
Core Foundation 70
Subclassing with Properties 70
Runtime Difference 71
Categories and Extensions 73
2011-10-12 | © 2011 Apple Inc. All Rights Reserved.
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