How do I convert an integer to a string in gnuplot?

Question

I know how to use $ with using in examples like

plot datafile using f($1):g($2)

to plot functions of column data. But

Answer 1

Prepend an empty string if necessary. E.g.:

gnuplot> a=42
gnuplot> print a." questions"
         internal error : STRING operator applied to non-STRING type

gnuplot> print "".a." questions"
42 questions

The first print fails because of a type mismatch. The second one works fine though. Apparently . is left associative.