루프 에서

루프 소개

while

def self.years_before_desired_balance(current_balance, desired_balance)
  years = 0
  while current_balance < desired_balance
    current_balance = annual_balance_update(current_balance)
    years += 1
  end
  years
end

until

def self.years_before_desired_balance(current_balance, desired_balance)
  years = 0
  until current_balance >= desired_balance
    current_balance = annual_balance_update(current_balance)
    years += 1
  end
  years
end

loop

def self.years_before_desired_balance(current_balance, desired_balance)
  years = 0
  loop do
    current_balance = annual_balance_update(current_balance)
    years += 1
    return years if current_balance >= desired_balance
  end
end

아마 눈치챘겠지만, Ruby에는 다른 언어들처럼 증가 연산자(i++)가 없어요. 대신 i += 1과 같은 표현(i = i + 1과 같아요)을 사용할 수 있어요.