메서드 정의하기

def say_hello
  puts 'Hello, Ruby!'
end

say_hello

def greet(name)
  puts "Hello, #{name}!"
end

greet('Alice')

def greet(name = 'Guest')
  puts "Hello, #{name}!"
end

greet

greet('Alice')

def square(number)
  return number * number
end

puts square(4)

def get_coordinates
  return 10, 20
end

x, y = get_coordinates
puts "X: #{x}, Y: #{y}"

def square(n)
  n * n
end

def cube(n)
  n * square(n)
end

puts cube(3)

def check_age(age)
  if age >= 18
    'Adult'
  else
    'Minor'
  end
end

puts check_age(20)