循环 属于

关于 循环

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

你可能已经注意到，Ruby 与其他一些语言不同，没有自增运算符（i++）。 相反，可以使用i += 1（等同于i = i + 1）这样的写法。