Task

In this exercise you are to use irb, a Ruby REPL, to evaluate various Ruby expressions and compile a list of observations about Ruby based on what you see.

Note: This exercise is to be entirely experimental. Don't Google, read documentation, etc. It's just your group and irb!

If you've got Ruby on your machine, irb should be there, too. On lectura, first do "rvm 2.2.4" and ignore any error output. Then do "irb".

Expressions to evaluate

Here are some suggested expressions to evaluate. Feel free to try additional expressions, too, such as expressions that work in languages you know.

3+4
_.class
7.<TAB><TAB>  # 7. then hit TAB twice
("abc"*3).size.to_s
s = RUBY_DESCRIPTION
s[5,9]
s[5..9]
s[-2]
"a test here".split.map {|s| s.size}
1032[3]
s=`cal; who | wc`   # backquotes!
s.gsub!("7","seven"); print s
"call 555-1212" =~ /[0-9]+/
[$`, $&, $']  # immediately after line above
('!'..'*').to_a
{ 1 => 2.0, :three => [!nil, "#{3+4}"] }
x = Complex(2,3) * 2 + 7
Rational(1,3) * 300
if 1 < 2 then 3 else 4 end
while line = gets; p line; end
print 1 unless 2 < 3
3.+(4)

Deliverable (per table)

Create a plain text file named cle7.txt with

A whitepace separated list of NetIDs for all tablemates

A list of ten observations about Ruby

Submit it on lectura with turnin:
turnin 372-cle7 cle7.txt

Note: We might browse the files when done. To be anonymous, put your NetIDs at the end of the file, preceded by about fifty blank lines.