Question

我正在尝试为数组设置边界，稍后将在控制台中打印并求和。下限（$ a）应该小于50并且我编写了这段代码来评估它，但是如果输入更高的数字，我希望它重新提示输入一个数字。到目前为止，谷歌和实验都让我失望。

def num_a
  print "Pick a number from 1 to 50: "
  $a = Integer(gets.chomp)
    until $a < 50
      puts "Um, try again please."
  # need something here to prompt for another response
  # until $a is less than 50
    end
end

Answer 1

您可以重新构建循环，以便提示和调用gets都在其中：

def num_a
  # start with a number that doesn't meet the condition
  a = 50

  # check if the number meets the condition yet
  until a < 50
    # ask the user to enter a number
    print "Pick a number from 1 to 50: "
    a = Integer(gets.chomp)
    # ask to try again if the number isn't under 50
    puts "Um, try again please." unless a < 50
  end

  # return the entered value to the caller
  a
end

此外，正如我在示例中所示，我建议避免使用全局变量（在这种情况下为$a）。

在一个简单的循环中重新尝试逻辑

1 个答案: