page 240, paragraph 4 from bottom : missing closing "
You can use the method banner to add a message to the top of this help listing as in parser.banner
= "Usage: option_1.rb [options]
-----> ^ <----- "
parser = OptionParser.new
parser.banner = "Usage: option_1.rb [options]
sort_type = nil
parser.on("-a", "Alphabetical") do
...
rubyworld/option_1.rb:16: syntax error, unexpected string literal, expecting `do' or '{' or '('
parser.on("-a", "Alphabetical") do