Re: camelCase vs snake_case

[Athanasius]

Here is a summary of the advice offered by the Camel Book (4th Edition, p. 704) on the naming of identifiers in Perl:

Identifier	Variable	Subroutine
Constant	$ALL_CAPS_HERE
Non-lexical filehandle	FILE
Package-wide global	$Some_Caps_Here
Package name	CamelCase
Lexicals and subs	$no_caps_here	process_data
Private to a package	$_leading_underscore	_frobnicate

I do not advocate this style merely because it happens to be the one recommended in the language’s definitive reference. (I personally dislike the K&R style it recommends for brace placement, pp. 701–2.) But in this case I think the advice is useful, because the different naming conventions aid the reader in distinguishing the different ways in which identifiers are used in code.

As sundialsvc4 and Tux have said, consistency is the key. In a coding environment where programmers are likely to ignore style guidelines, a single one-case-fits-all style may be preferable (because easier to enforce). But in the general case, the visual distinctions provided by the various naming styles listed above aid comprehension and are worth learning, IMO.