如果它们具有相同的值，则在哈希数组中求和值 [英] Sum values in array of hash if they have the same value

问题描述

Rails在哈希数组中加上数值

  array = [
 {loading：10，avg：15，total：25}，
 {loading：20，avg：20，总数：40}，
 {loading：30，avg：25，total：55} 
] 
 
 sum = Hash.new（0）
 
 array.each_with_object（sum）do | hash，sum | 
 hash.each {| key，value | sum [key] + = value} 
 end 
＃=> {：loading => 60，：avg => 60，：total => 120} 
  

我想要做什么，我不知道怎么做，是总和的关键，如果加载和avg出现在这个数组中多次相同的值。例如。

  array = [
 {loading：10，avg：15，total：25}，
 {loading：20，avg：20，total：40}，＃看到这里
 {loading：30，avg：25，total：55}，
 {loading：20，avg：20，总数：80}，＃见这里
 {loading：10，avg：20，total：46} 
] 
  

结果如下：

$ p $ [
{loading：10，avg： 15，总数：25}，
{loading：20，avg：20，total：120}，＃结果在
{loading：30，avg：25，total：55}，
{loading：10，avg：20，total：46}
]


修改此行

  hash.each {| key，value | sum [key] + = value} 
  

添加一个条件来检查值是否重复但我didn没有成功。

任何帮助，想法或任何东西都会受到欢迎。 这似乎工作

  array.group_by {| item | [item [：loading]，item [：avg]]} .values.flat_map {| items | items.first.merge（total：items.sum {| h | h [：total]}）} 
 => [{：loading => 10，：avg => 15，：total => 25}，{：loading => 20，：avg => 20，：total => 120}，{：loading => 30，：：avg => 25，：total => 55}，{：loading => 10，：avg => 20，：total => 46}] 
  

I saw this piece of code in this post, because I'm trying to sum values in an array of hashes based on some criteria.

Rails sum values in an array of hashes

array = [
  {loading: 10, avg: 15, total: 25 },
  {loading: 20, avg: 20, total: 40 },
  {loading: 30, avg: 25, total: 55 }
]

sum = Hash.new(0)

array.each_with_object(sum) do |hash, sum|
  hash.each { |key, value| sum[key] += value }
end
 # => {:loading=>60, :avg=>60, :total=>120}

What I'm trying to do and I don't know how, is to sum total key if loading and avg appear with the same values more than once in this array. For instance.

 array = [
      {loading: 10, avg: 15, total: 25 },
      {loading: 20, avg: 20, total: 40 }, # See here
      {loading: 30, avg: 25, total: 55 },
      {loading: 20, avg: 20, total: 80 }, # See here
      {loading: 10, avg: 20, total: 46 }
    ]

The result would be:

[
  {loading: 10, avg: 15, total: 25 },
  {loading: 20, avg: 20, total: 120 }, # Results in this
  {loading: 30, avg: 25, total: 55 },
  {loading: 10, avg: 20, total: 46 }
]

I tried to modify this line

hash.each { |key, value| sum[key] += value }

Adding a conditional that checks if the value is repeated but I didn't succeed.

Any help, ideas or anything will be welcome.

解决方案

This seems work

array.group_by { |item| [item[:loading], item[:avg]] }.values.flat_map { |items| items.first.merge(total: items.sum { |h| h[:total] }) }
=> [{:loading=>10, :avg=>15, :total=>25}, {:loading=>20, :avg=>20, :total=>120}, {:loading=>30, :avg=>25, :total=>55}, {:loading=>10, :avg=>20, :total=>46}]

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