• Why Have Error Objects?

• Error Domains

• Error Codes

• The User Info Dictionary

• Localized Error Information

• The Recovery Attempter

• Underlying Error

• Domain-Specific Keys

• The Error-Responder Chain

• Error Customization

• Error Recovery

• Handling Error Objects Returned From Methods

• Displaying Information From Error Objects

• Creating and Returning NSError Objects

• A Note on Errors and Exceptions

• Passing Errors Up the Error-Responder Chain

• Customizing an Error Object