[讀書筆記] Effective Objective-C - Chapter3

3. Interface and API Design

Item 15: Use Prefix Names to Avoid Namespace Clashes

1. Choose a class prefix that befits your company, application, or both. Then stick with that prefix throughout.
2. If you use a third-party library as a dependency of your own library, consider prefixing its names with your prefix. 

Item 16: Have a Designated Initializer

1. Throw an exception in initializers overridden from superclasses that should not be used in the subclass. 

Item 17: Implement the description Method

1. -(NSString*)description,   -(NSString*)debugDescription

Item 18: Prefer Immutable Objects

Item 19: Use Clear and Consistent Naming

1. Verbose but clear naming of methods is more acceptable in Objective-C than in other languages.
2. Avoid abbreviations, such as str, and instead use full names, such as string.

Item 20: Prefix Private Method Names

1. Suggestion: Use "p_" as prefix for private methods.
2. Avoid using single "_" as the method prefix, since this is reserved by Apple.

Item 21: Understand the Objective-C Error Model

1. Any objects that should be released at the end of a scope in which an exception is thrown will not be released. (-fobjc-arc-exceptions)

Item 22: Understand the NSCopying Protocol

1. To support copying: 
1. Implement NSCopying protocol. 
2. Override -(id)copyWithZone:(NSZone*)zone or -(id)mutableCopyWithZone:(NSZone*)zone 
2. If your object has mutable and immutable variants, implement both the NSCopying and NSMutableCopying protocols.