Naming Functions

Objective-C allows you to express behavior through functions as well as methods. You should use functions rather than, say, class methods, when the underlying object is always a singleton or when you are dealing with obviously functional subsystems.

Functions have some general naming rules that you should follow:

Function names are formed like method names, but with a couple exceptions:
- They start with the same prefix that you use for classes and constants.
- The first letter of the word after the prefix is capitalized.
Most function names start with verbs that describe the effect the function has:

NSHighlightRect

NSDeallocateObject

Functions that query properties have a further set of naming rules:

If the function returns the property of its first argument, omit the verb.

unsigned int NSEventMaskFromType(NSEventType type)

float NSHeight(NSRect aRect)

If the value is returned by reference, use “Get”.

const char *NSGetSizeAndAlignment(const char *typePtr, unsigned int *sizep, unsigned int *alignp)

If the value returned is a boolean, the function should begin with an inflected verb.
BOOL NSDecimalIsNotANumber(const NSDecimal *decimal)

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Last updated: 2006-04-04

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