Why use prefixes on member variables in C++ classes

Question

A lot of C++ code uses syntactical conventions for marking up member variables. Common examples include

• m_memberName for public members (where public

Answer 1

Some responses focus on refactoring, rather than naming conventions, as the way to improve readability. I don't feel that one can replace the other.

I've known programmers who are uncomfortable with using local declarations; they prefer to place all the declarations at the top of a block (as in C), so they know where to find them. I've found that, where scoping allows for it, declaring variables where they're first used decreases the time that I spend glancing backwards to find the declarations. (This is true for me even for small functions.) That makes it easier for me to understand the code I'm looking at.

I hope it's clear enough how this relates to member naming conventions: When members are uniformly prefixed, I never have to look back at all; I know the declaration won't even be found in the source file.

I'm sure that I didn't start out preferring these styles. Yet over time, working in environments where they were used consistently, I optimized my thinking to take advantage of them. I think it's possible that many folks who currently feel uncomfortable with them would also come to prefer them, given consistent usage.