Interview Questions that may be asked on C++

First off the best way of preparing for an interview is to go to plenty. Just see what sort of things people want you to know and always ask them for feedback afterwards. Most interviewers are pretty candid about what they think you did well or not.

That being said whenever I interview someone for a job that requires C++ coding there are a couple of questions I always ask when we get to the technical bit of the interview started. They're a good initial barometer of how some much someone knows.

1. Tell me how you'd generally write an exception safe assignment operator for a class?

2. Say you've got a text file of integers. How would you open the file, add one to each number and write them back out to a file?

[Keep getting the candidate to refine their answer until it's down to open a couple of files one other line]

The first one shows they've got some understanding of how exceptions interact with the rest of C++ works and a bit about RAII. All the details about it can be found in the first chunk of "Exceptional C++" by Herb Sutter.

The second one shows if they've ever used the STL and streams in any meaningful way. The final three line solution (without error checking) is something like:

std::ifstream input( "input.txt" );
std::ofstream output( "output.txt" );

std::transform( std::istream_iterator<int>( input ),
                std::istream_iterator<int>(),
                std::ostream_iterator<int>( output, " " ),
                std::bind2nd( std::plus<int>(), 1 ) );

Anyway, no idea if this lot'll help but it's always handy to know!

Cheers,

Ash