00-preface.rb

O Reilly Ruby Cookbook source code

1 + 2                                                 # => 3

# On a long line, the expected value goes on a new line:
Math.sqrt(1 + 2 + 3 + 4 + 5 + 6 + 7 + 8 + 9 + 10)
# => 7.41619848709566
#---
puts "This string is self-referential."
# This string is self-referential.
#---
$ irb
irb(main):001:0> 1 + 2
=> 3
irb(main):002:0> Math.sqrt(1 + 2 + 3 + 4 + 5 + 6 + 7 + 8 + 9 + 10)
=> 7.41619848709566
irb(main):003:0> puts "This string is self-referential."
This string is self-referential.
=> nil
#---
$ irb
irb(main):001:0> 1 + 2      # => 3
=> 3
irb(main):002:0>
irb(main):003:0* # On a long line, the expected value goes on a new line:
irb(main):004:0* Math.sqrt(1 + 2 + 3 + 4 + 5 + 6 + 7 + 8 + 9 + 10)
=> 7.41619848709566
irb(main):005:0> # => 7.41619848709566
irb(main):006:0*
irb(main):007:0* puts "This string is self-referential."
This string is self-referential.
=> nil
irb(main):008:0> # This string is self-referential.
#---
#!/usr/bin/ruby -w
# sample_ruby_file.rb: A sample file

1 + 2
Math.sqrt(1 + 2 + 3 + 4 + 5 + 6 + 7 + 8 + 9 + 10)
puts "This string is self-referential."
#---
$ ruby sample_ruby_file.rb
This string is self-referential.
#---
$ ruby setup.rb
#---
$ gem install rails --include-dependencies
#---
$ ri Array                                  # A class
$ ri Array.new                              # A class method
$ ri Array#compact                          # An instance method
#---