2.1.3 method declaration syntax

example.rb

# All of the following method declarations are equivalent. (They all have the same result)
# The only difference is in how they are called.

some_data = {required_argument: 'bob', optional_argument: 'dole'}

# Pre 2.1.3 style
def some_method(required_argument, optional_requirement = nil)
  p [required_argument, optional_argument]
end

some_method()# => ArgumentError: wrong number of arguments (0 for 1..2)
some_method('bob')# => "['bob',nil]"
some_method('bob', 'dole')# => "['bob','dole']"
some_method(some_data)# => "[{required_argument: 'bob', optional_argument: 'dole'},nil]"

# Pre 2.1.3 style using named keywords
def some_method(required_argument: nil, optional_argument: nil)
  raise ArgumentError, 'wrong number of arguments (0 for 1..2)' if required_argument.nil?
  p [required_argument, optional_argument]
end

some_method()# => ArgumentError: wrong number of arguments (0 for 1..2)
some_method(required_argument: 'bob')# => "['bob',nil]"
some_method('bob', 'dole')# => "['bob','dole']"
some_method(some_data)# => "['bob','dole']"

# 2.1.3 style using named keywords
def some_method(required_argument:, optional_argument: nil)
  p [required_argument, optional_argument]
end


some_method()# => ArgumentError: missing keyword: required_argument
some_method(required_argument: 'bob')# => "['bob',nil]"
some_method('bob', 'dole')# => ArgumentError: missing keyword: required_argument
some_method(some_data)# => "['bob','dole']"