Question

I’ve been programming for years, but I can never quite decide the correct place to comment on the function of a for loop. Before, to the right, or after?

// iterate over rows, blah blah...
for (std::string row : csv) {
    ...
}
for (std::string row : csv) { // iterate over rows, blah blah...
    ...
}
for (std::string row : csv) {
    // iterate over rows, blah blah...
    ...
}

Commenting to the right saves a line, but is less readable and tends to make the line go over 80 characters. Commenting below kind of works, but that may be where I place the comment for the first block of code within the for loop. What’s your preferred style and why?

Answer 1

The most widespread commenting style I’ve seen is commenting before doing, so I prefer the first option. It is simply more consistent with the commenting style in the rest of the code, i.e., it does not give a specific treatment to loops.