在Ruby中从哈希数组中删除一个哈希

Question

我有一个哈希数组如下：

[{"k1"=>"v1", "k2"=>"75.1%"}, {"k1"=>"v2", "k2"=>"-NA-"}, {"k1"=>"v3", "k2"=>"5.1%"}]

现在，我想先检查数组中是否包含具有键"k1"和值"v3"的哈希表。如果是，则删除该哈希表。

结果应为：

[{"k1"=>"v1", "k2"=>"75.1%"}, {"k1"=>"v2", "k2"=>"-NA-"}]

- user2823083

Answer 1

使用Array#delete_if方法：

arr = [{"k1"=>"v1", "k2"=>"75.1%"}, {"k1"=>"v2", "k2"=>"-NA-"}, {"k1"=>"v3", "k2"=>"5.1%"}]

arr.delete_if { |h| h["k1"] == "v3" }
#=> [{"k1"=>"v1", "k2"=>"75.1%"}, {"k1"=>"v2", "k2"=>"-NA-"}]

如果没有符合条件的哈希值，数组将保持不变。

- Stefan

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如果我想在else情况下执行某些操作，例如h["k1"] != "v3"。我们该怎么做？ - Hellboy

Answer 2

你可以使用 Array＃reject（如果你不想修改接收器）或者 Array＃reject！（如果你想修改接收器）。

arr = [{"k1"=>"v1", "k2"=>"75.1%"}, {"k1"=>"v2", "k2"=>"-NA-"}, {"k1"=>"v3", "k2"=>"5.1%"}]
p arr.reject { |h| h["k1"] == "v3" }
# >> [{"k1"=>"v1", "k2"=>"75.1%"}, {"k1"=>"v2", "k2"=>"-NA-"}]    

arr = [{"k1"=>"v1", "k2"=>"75.1%"}, {"k1"=>"v2", "k2"=>"-NA-"}, {"k1"=>"v3", "k2"=>"5.1%"}]
p arr.reject! { |h| h["k1"] == "v3" }
# >> [{"k1"=>"v1", "k2"=>"75.1%"}, {"k1"=>"v2", "k2"=>"-NA-"}]

- Arup Rakshit

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我能用这个来拒绝多个数组元素吗？ - harika