What is the definition of Convenience Method in regards to Objective C?

objective-c ios definition convenience-methods
Stefan H picture Stefan H · Feb 23, 2011 · Viewed 8.4k times · Source

In most languages I have dealt with, one something is called a convenience method, it means that the method does some small task that gets done very frequently, and therefore it is more convenient to use said method.

In Objective-C does this definition hold true? Or is it generally only used to describe class methods that return a prebuilt object? ex. [NSString stringWithContentsOfFile:...]

Is this just a preference thing, or are there some hard and fast definition for these terms?

Cheers, Stefan

Answer

Andy White picture Andy White · Feb 23, 2011

What you are talking about is actually more specifically a "convenience constructor" in Objective C. (Note that it's not really a constructor in the C++/Java/C# sense, it's actually an object initializer/factory method, but it seems to be the convention to call the "convenience constructors"). "Convenience constructors" in Obj C are a convention or pattern for creating a constructor/initializer/factory method for a class which takes specific parameters. This pattern also has some special conventions that you should follow (such as autoreleasing the new object within the constructor), so that your custom classes fit in well with the built-in types.

See this page (a little way down) for more info: http://macdevcenter.com/pub/a/mac/2001/07/27/cocoa.html?page=3

As for "convenience method," this specific term doesn't have any special meaning in Objective C. You can create any type of convenience method in Obj C, and there is no expectation about what it should or should not do. It's only "convenience constructor" that has a special meaning.

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