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What is the correct possessive for nouns ending in s?
I want to write this sentence:
In a singleton pattern, a class's constructor needs to be private instead of public.
it is correct to write:
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That would be class' or class's, but I would rather change the sentence to avoid that altogether.
Also, as it's a specific pattern that is applied to a specific class, it would be more correct to refer to the pattern and the class instead of a pattern and a class:
In the singleton pattern, the constructor of the class needs to be private instead of public.
As the pattern is something that only is applied to a class, it can even be implied:
In the singleton pattern, the constructor needs to be private instead of public.
The Chicago Manual of Style, 14th edition says:
6.19: The possessive of singular nouns is formed by the addition of an apostrophe and an s [...]
There are a few exceptions listed later on, but they do not apply to a common noun ending in s (or ss).
Thus I say that
a class's constructor
is correct.
Both "a class' constructor" and "a class's constructor" are accepted as correct. More recent English use stylistic guides show preference for the "a class's constructor" use.
