Question

说我有这样的数组：

["auburn", "http://auburn.craigslist.org/web/", "http://auburn.craigslist.org/cpg/", "http://auburn.craigslist.org/eng/", "http://auburn.craigslist.org/sof/", "http://auburn.craigslist.org/sad/"]

我想要做的只是处理此数组中的网址 - 这些网址始终位于element[1]并上线。

我该怎么做？

Answer 1

这仅显示从1开始的元素（第二个元素），-1代表最后一个元素

a = ["auburn", "http://auburn.craigslist.org/web/", "http://auburn.craigslist.org/cpg/", "http://auburn.craigslist.org/eng/", "http://auburn.craigslist.org/sof/", "http://auburn.craigslist.org/sad/"] 

p a[1..-1]
=> ["http://auburn.craigslist.org/web/", "http://auburn.craigslist.org/cpg/", "http://auburn.craigslist.org/eng/", "http://auburn.craigslist.org/sof/", "http://auburn.craigslist.org/sad/"]

Answer 2

a = ["auburn", "http://auburn.craigslist.org/web/", "http://auburn.craigslist.org/cpg/", "http://auburn.craigslist.org/eng/", "http://auburn.craigslist.org/sof/", "http://auburn.craigslist.org/sad/"]

a.drop(1).each { |m| puts m }

#=> http://auburn.craigslist.org/web/
#   http://auburn.craigslist.org/cpg/
#   http://auburn.craigslist.org/eng/
#   http://auburn.craigslist.org/sof/
#   http://auburn.craigslist.org/sad/

Answer 3

a [1 ..- 1]将返回数组，并删除第一个项目。

Answer 4

只需选择所需的元素即可：

a.grep(/^http:/).each { ... }

或者，如果您不希望不必要地创建新的阵列副本：

a.each { |e| 
  next if !e.match(/^http:/)
  ...
}

Answer 5

尝试切片：

arr = ["auburn", "http://auburn.craigslist.org/web/", "http://auburn.craigslist.org/cpg/", "http://auburn.craigslist.org/eng/", "http://auburn.craigslist.org/sof/", "http://auburn.craigslist.org/sad/"]
arr.slice(1..-1)

修改：

使用它像：

arr.slice(1..-1).each do |p|
  puts p
end

如何使用每个元素从第二个元素开始在数组中循环？ - Ruby

5 个答案: