Ruby on rails 在散列中减去值

我想从两个散列中减去两个值。了解我的成长三角洲

我的哈希如下所示：

[
 {:device=>"router", :portmax=>"Port 1/5/3:2006.0", :discardmax=>16617331511, :timeCapturedmax=>"February 18, 2018 at 09:27 AM", :time_unixmax=>1518964024}, 
 {:device=>"router", :portmax=>"Port 1/5/3:2006.0", :discardmax=>16617216094, :timeCapturedmax=>"February 18, 2018 at 09:22 AM", :time_unixmax=>1518963724}, 
 {:device=>"router", :portmax=>"Port 1/5/3:2006.0", :discardmax=>16617202279, :timeCapturedmax=>"February 18, 2018 at 09:18 AM", :time_unixmax=>1518963485}, 
 {:device=>"router", :portmax=>"Port 1/5/3:2006.0", :discardmax=>16616985649, :timeCapturedmax=>"February 18, 2018 at 09:12 AM", :time_unixmax=>1518963135}, 
 {:device=>"router", :portmax=>"Port 1/5/3:2006.0", :discardmax=>16616404836, :timeCapturedmax=>"February 18, 2018 at 09:07 AM", :time_unixmax=>1518962829},  
 {:device=>"router", :portmax=>"Port 1/5/3:2006.0", :discardmax=>16616368250, :timeCapturedmax=>"February 18, 2018 at 09:03 AM", :time_unixmax=>1518962583}
]

因此，我希望：

Rate_Discard = [{:device=>"router", :discard_sub=>115417}, {:device=>"router", :discard_sub=>13815}, {:device=>"router", :discard_sub=>216630}]

---

如果您的数组是

arr

，

arr[0][：discardmax]-arr[1][：discardmax]#=>115417

，

arr[1][：discardmax]-arr[2][：discardmax]#=>13815

和

arr[2][：discardmax]-arr[3][：discardmax]#=>216630

。其他三对（2->3、3->4和4->5）的情况如何？您有一个哈希数组，而不是哈希。当您给出一个示例时，为每个输入对象分配一个变量会很有帮助。这里您只有一个输入对象，一个哈希数组，因此您可以将变量

arr

分配给它，正如我在回答中所做的那样。通过这种方式，读者可以在答案和注释中引用这些变量（此处仅为

arr

），而无需定义它们。“我希望得到以下结果”-当开发人员希望得到结果时，正确的操作是编写代码。您好，如果我有此数组：

arr = [
  {:device=>"router", :portmax=>"Port 1/5/3:2006.0", :discardmax=>16617331511, 
     :timeCapturedmax=>"February 18, 2018 at 09:27 AM", :time_unixmax=>1518964024},
  {:device=>"router", :portmax=>"Port 1/5/3:2006.0", :discardmax=>16617216094,
     :timeCapturedmax=>"February 18, 2018 at 09:22 AM", :time_unixmax=>1518963724},
  {:device=>"router", :portmax=>"Port 1/5/3:2006.0", :discardmax=>16617202279,
     :timeCapturedmax=>"February 18, 2018 at 09:18 AM", :time_unixmax=>1518963485},
  {:device=>"router", :portmax=>"Port 1/5/3:2006.0", :discardmax=>16616985649,
     :timeCapturedmax=>"February 18, 2018 at 09:12 AM", :time_unixmax=>1518963135},
  {:device=>"router", :portmax=>"Port 1/5/3:2006.0", :discardmax=>16616404836,
     :timeCapturedmax=>"February 18, 2018 at 09:07 AM", :time_unixmax=>1518962829},
  {:device=>"router", :portmax=>"Port 1/5/3:2006.0", :discardmax=>16616368250,
     :timeCapturedmax=>"February 18, 2018 at 09:03 AM", :time_unixmax=>1518962583}
]

arr.each_cons(2).map do |g,h|
  { device: g[:device], discard_sub: g[:discardmax]-h[:discardmax] }
end
  #=> [{:device=>"router", :discard_sub=>115417},
  #    {:device=>"router", :discard_sub=>13815},
  #    {:device=>"router", :discard_sub=>216630},
  #    {:device=>"router", :discard_sub=>580813},
  #    {:device=>"router", :discard_sub=>36586}]