Ruby -如何删除哈希数组中的重复项？
Ruby -如何删除哈希数组中的重复项？
提问于 2018-06-21 19:44:15
我在一个哈希数组中有一个哈希数组。我想根据内部数组的值删除重复项。
topics = [{"defense"=>
[{:id=>30,
:source=>"Hacker News",
:title=>
"China-based campaign breached satellite, defense companies: Symantec",
:link=>
"https://www.reuters.com/article/us-china-usa-cyber/china-based-campaign-breached-satellite-defense-companies-symantec-idUSKBN1JF2X0"}]},
{"companies"=>
[{:id=>30,
:source=>"Hacker News",
:title=>
"China-based campaign breached satellite, defense companies: Symantec",
:link=>
"https://www.reuters.com/article/us-china-usa-cyber/china-based-campaign-breached-satellite-defense-companies-symantec-idUSKBN1JF2X0"}]},
{"Symantec"=>
[{:id=>30,
:source=>"Hacker News",
:title=>
"China-based campaign breached satellite, defense companies: Symantec",
:link=>
"https://www.reuters.com/article/us-china-usa-cyber/china-based-campaign-breached-satellite-defense-companies-symantec-idUSKBN1JF2X0"}]}]
topics.uniq { |phrase, post| post }
puts topics您可以在上面看到短语defense、companies和Symantec各自包含相同的数组。如何只保留包含相同数组之一的第一个散列？
预期输出：
{"defense"=>
[{:id=>30,
:source=>"Hacker News",
:title=>
"China-based campaign breached satellite, defense companies: Symantec",
:link=>
"https://www.reuters.com/article/us-china-usa-cyber/china-based-campaign-breached-satellite-defense-companies-symantec-idUSKBN1JF2X0"}]}注意:在上面的示例中，每个“短语”的内部数组只包含一个散列，但在应用程序中，它可以包含多个帖子。
回答 3
Stack Overflow用户
发布于 2018-06-21 20:33:38
对于每个唯一的值，topics.invert.invert会将散列减少为一个(任意选择的)键。
Stack Overflow用户
发布于 2018-06-21 21:39:05
使用此解决方案，您只能获得数组：
topics.map { |topic| topic.values }.uniq.flatten 它只返回：
# => [{:id=>30, :source=>"Hacker News", :title=>"China-based campaign breached satellite, defense companies: Symantec", :link=>"https://www.reuters.com/article/us-china-usa-cyber/china-based-campaign-breached-satellite-defense-companies-symantec-idUSKBN1JF2X0"}]Stack Overflow用户
发布于 2018-06-22 09:55:18
topics = [
{ "defense" => [{ id: 30, source: "Hacker", title: "China", link: "F2X0"}] },
{ "companies" => [{ id: 30, source: "Hacker", title: "China", link: "F2X0"}] },
{ "Symantec" => [{ id: 30, source: "Hacker", title: "China", link: "F2X0"}] }
]
topics.uniq { |h| h.values }
#=> [{"defense"=>[{:id=>30, :source=>"Hacker", :title=>"China", :link=>"F2X0"}]}]有关uniq使用块的情况，请参阅Array#uniq。请注意这句话："self是按顺序遍历的，并且保留第一个出现的内容。“
页面原文内容由Stack Overflow提供。腾讯云小微IT领域专用引擎提供翻译支持
原文链接：
https://stackoverflow.com/questions/50967781
复制相关文章
相似问题
腾讯云开发者
