logical_operator_precedence.rb

# Logical operator precedence in Ruby
#
# Problems might arise in combination with the assignment operator.
#
# http://blog.jayfields.com/2007/08/ruby-operator-precedence-of-and-which.html
# http://phrogz.net/ProgrammingRuby/language.html#table_18.4

# Definitions:
# '&&' and '||' are logical operators
# 'and' and 'or' are logical composition operators

#
# '&&' compared to 'and'
#

  a = true && false    # => false
#     \___________/
  a                    # => false
  b = true and false   # => false
# \______/
  b                    # => true (!)
  c = (true and false) # => false
#     \______________/
  c                    # => false

#
# '||' compared to 'or'
#

  d = false || true    # => true
#     \___________/
  d                    # => true
  e = false or true    # => true
# \_______/
  e                    # => false (!)
  f = (false or true)  # => true
#     \_____________/
  f                    # => true