Time.now

Time::now

def greet
  puts 'hola'
end

greet

undef greet

greet

alias greet puts

greet 'hi'

greet 'No thank you'

undef puts

puts 'hoge'

greet 'fuga'

alias puts greet

puts 'foo'

def foo
  raise
end

foo

alias bar foo

bar

undef foo

bar

puts 1
puts "hoge\n"
puts "Python", "Ruby"

print "Hi"
print 1, 2, 'hoge'

sprintf '%04d', 1

format '%04d', 1

'%04d !!!!! %s' % [1, 'yeyyey']

'あなたは%04d人目の来訪者です' % [10]

num = 10
"ほげ#{num}人目"

'あなたは%<num>04d人目の来訪者です' % {num: 10}

/(?<num>\d+)人目/ =~ '10人目'

p num

/(?<num2>\d+)人目/.match '10人目'

num2

'10人目' =~ /(?<num3>\d+)人目/

num3

m = /(?<num2>\d+)人目/.match '10人目'
m[:num2]