所以,我的怀疑很简单。
我有一个数组,我的目标是以某种方式打印代码,以便输出以下内容:
我该怎么做?
感谢。
答案 0 :(得分:7)
我想有很多宝石可以做到这一点,但如果你想自己动手,你可以这样做,以一种相当普遍的方式:
您的输入由列标签组成:
col_labels = { date: "Date", from: "From", subject: "Subject" }
和行的数据:
arr = [{date: "2014-12-01", from: "Ferdous", subject: "Homework this week"},
{date: "2014-12-01", from: "Dajana", subject: "Keep on coding! :)"},
{date: "2014-12-02", from: "Ariane", subject: "Re: Homework this week"}]
其中col_labels
和arr
的元素具有相同的键。
从这一点开始,代码是通用的。首先构造一个哈希@columns
(为方便起见,我已经创建了一个实例变量)。
@columns = col_labels.each_with_object({}) { |(col,label),h|
h[col] = { label: label,
width: [arr.map { |g| g[col].size }.max, label.size].max } }
# => {:date=> {:label=>"Date", :width=>10},
# :from=> {:label=>"From", :width=>7},
# :subject=> {:label=>"Subject", :width=>22}}
def write_header
puts "| #{ @columns.map { |_,g| g[:label].ljust(g[:width]) }.join(' | ') } |"
end
def write_divider
puts "+-#{ @columns.map { |_,g| "-"*g[:width] }.join("-+-") }-+"
end
def write_line(h)
str = h.keys.map { |k| h[k].ljust(@columns[k][:width]) }.join(" | ")
puts "| #{str} |"
end
write_divider
write_header
write_divider
arr.each { |h| write_line(h) }
write_divider
+------------+---------+------------------------+
| Date | From | Subject |
+------------+---------+------------------------+
| 2014-12-01 | Ferdous | Homework this week |
| 2014-12-01 | Dajana | Keep on coding! :) |
| 2014-12-02 | Ariane | Re: Homework this week |
+------------+---------+------------------------+
如果您想要反转显示并使其大一点,就像您的一样,首先执行:
$_!.reverse
$_@ += 4