Ruby Programming/Alternate quotes
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In Ruby, there's more than one way to quote a string literal. Much of this will look familiar to Perl programmers.
[edit] Alternate single quotes
Let's say we are using single quotes to print out the following path.
puts 'c:\bus schedules\napolean\the portland bus schedule.txt'
The single quotes keep the \b, \n, and \t from being treated as escape sequences. But consider the following string literal.
puts 'c:\napolean\'s bus schedules\tomorrow\'s bus schedule.txt'
Escaping the apostrophes makes the code less readable and makes it less obvious what will print out. Luckily, in Ruby, there's a better way. You can use the %q operator to apply single-quoting rules, but choose your own delimiter to mark the beginning and end of the string literal.
puts %q!c:\napolean's documents\tomorrow's bus schedule.txt!
puts %q/c:\napolean's documents\tomorrow's bus schedule.txt/
puts %q^c:\napolean's documents\tomorrow's bus schedule.txt^
puts %q(c:\napolean's documents\tomorrow's bus schedule.txt)
puts %q{c:\napolean's documents\tomorrow's bus schedule.txt}
puts %q<c:\napolean's documents\tomorrow's bus schedule.txt>
Each line will print out the same text – "c:\napolean's documents\tomorrow's bus schedule.txt". You can use any punctuation you want as a delimiter, not just the ones listed in the example.
Of course, if your chosen delimiter appears inside of the string literal, then you need to escape it.
puts %q#c:\napolean's documents\tomorrow's \#9 bus schedule.txt#
If you use matching braces to delimit the text, however, you can nest braces, without escaping them.
puts %q(c:\napolean's documents\the (bus) schedule.txt)
puts %q{c:\napolean's documents\the {bus} schedule.txt}
puts %q<c:\napolean's documents\the <bus> schedule.txt>
[edit] Alternate double quotes
The %Q operator allows you to create a string literal using double-quoting rules, but without using the double quote as a delimiter. It works much the same as the %q operator.
print %Q^Say:\tHello world\n\tHello world\n^ print %Q(Say:\tHello world\n\tHello world\n)
Just like double quotes, you can interpolate Ruby code inside of these string literals.
name = 'Charlie Brown'
puts %Q!Say "Hello," #{name}.!
puts %Q/What is "4 plus 5"? Answer: #{4+5}/
