The ?'s and :'s seen in the spreadsheet cells are part of compact notation for an if-then-else clause. Something like:

\texttt{( B2 > 16 ? 'passing grade' : 'failing grade')}

can be translated into:

\texttt{if (B2 > 16 ) \{ \\
  \hspace*{16pt}     \$temp = 'passing grade';\\
  \} else \{ \\
  \hspace*{16pt}     \$temp = 'failing grade'; \\
  \} \\
  \$temp;\\
}

The nicest part of the ( ? : ) operator (aside from its compactness)
is the way it automatically returns the value you want without having
to use any temporary variable.s