RUBY

ruby define_method?

class Bar
  define_method(:initialize) do |*pos_params, **named_params, &block|
    @pos_params = pos_params
    @named_params = named_params
    block.call(self) if block
  end
  define_method(:one_optional_arg) do |arg=nil|
    puts arg
  end   
  define_method(:some_args) do |*args|
    puts args.join(', ')
  end
  define_method(:my_name_and_args) do |name, *args|
    puts [name, *args].join(' ')
  end
  define_method(:some_opts) do |**opts|
    puts opts.inspect
  end
  define_method(:named_arg_plus_opts) do |name:, **opts|
    puts({ name: name }.merge(opts).inspect)
  end
  def print
    puts @pos_params.join(', ')
    puts @named_params.inspect
  end
end

foo = Bar.new
foo.one_optional_arg                          # => 
foo.one_optional_arg 'one'                    # => 'one'

foo.some_args                                 # => 
foo.some_args 'Hello', 1, :world              # => Hello, 1, world

# foo.my_name_and_args                        # => ERROR wrong number of arguments (given 0, expected 1+)
foo.my_name_and_args 'David'                  # => David
foo.my_name_and_args 'David', 'was', 'here'   # => David was here

foo.some_opts                                 # => {}
foo.some_opts a: 1, b: 2                      # => {:a=>1, :b=>2}

# foo.named_arg_plus_opts                     # => ERROR missing keyword: :name
foo.named_arg_plus_opts name: 'David'         # => {:name=>"David"}
foo.named_arg_plus_opts name: 'David', role: 'developer'  
											  # => {:name=>"David", :role=>"developer"}

BarConstructor.new('The', 'quick', 'brown', 'fox', color: :brown, animal: 'Fox') do |bar|
  bar.print
  # The, quick, brown, fox
  # {:color=>:brown, :animal=>"Fox"}
end

how to create a method ruby

#start with 'def', name the method, add function, end with 'end'
def this_method_multiples_x_by_number_of_students
  x * number_of_students
end
# => class_name.this_method_multiples_x_by_number_of_students

Ruby | Methods

# Ruby program to illustrate the defining
# and calling of method
 
#!/usr/bin/ruby
 
# Here geeks is the method name
def geeks
 
# statements to be displayed
puts "Welcome to GFG portal"
 
# keyword to end method
end
 
# calling of the method
geeks

Ruby | Methods

# Ruby program to illustrate the parameter
# passing to methods
 
#!/usr/bin/ruby
 
# geeks is the method name
# var1 and var2 are the parameters
def geeks (var1 = "GFG", var2 = "G4G")
 
     #  statements to be executed
     puts "First parameter is #{var1}"
     puts "First parameter is #{var2}"
end
 
# calling method with parameters
geeks "GeeksforGeeks", "Sudo"
 
puts ""
 
puts "Without Parameters"
puts ""
 
# calling method without passing parameters
geeks

Ruby | Methods

# Ruby program to illustrate the method
# that takes variables number of arguments
 
#!/usr/bin/ruby
 
# defining method geeks that can
# take any number of arguments
def geeks (*var)
     
   # to display the total number of parameters
   puts "Number of parameters is: #{var.length}"
    
   # using for loop
   for i in 0...var.length
      puts "Parameters are: #{var[i]}"
   end
end
 
# calling method by passing
# variable number of arguments
geeks "GFG", "G4G"
geeks "GeeksforGeeks"

Ruby | Methods

# Ruby program to illustrate method return statement
 
#!/usr/bin/ruby
 
# geeks is the method name
def num
 
# variables of method
a = 10
b = 39
 
sum = a + b
 
# return the value of the sum
return sum
 
end
 
# calling of num method
puts "The result is: #{num}"

ruby method

def print_args(arg1,ar2)
	puts arg1
    puts arg2
end