Why doesn't interpolation of constants work with percent notation in Ruby

Question

This doesn't work:

FOOBAR = 'foobar'
%W{ FOOBAR }

output: ["FOOBAR"]

However, the constant gets interpolated correctly by:

"#{FOOBAR}"
output: "foobar"

Answer 1

You're misusing %W literal. From book:

%W - Interpolated Array of words, separated by whitespace

so it doesn't have anything to do with interpolation.