I have a section array ['part one','part two'] and an array of item objects [item1,item2,item3].
我有一个剖面数组['part one'，'part two']和一个项目对象数组[item1，item2，item3]。
Each item object has a section attribute ( in this case with the value of 'part one' or'part two') and an order attribute which is an integer.
每个item对象都有一个section属性（在本例中为'part one'或'part two'的值）和一个order属性，它是一个整数。
I want to create an array like
我想创建一个像这样的数组
[ ['part one',[item1,item3]],['part two',[item3]] ]
or
要么
[['part one',item1,item3],['part two',item3]]
where
哪里
item1.section == 'part one' and item1.order == 1,
item3.section == 'part one' and item3.order == 2,
item2.section == 'part two' and item2.order == 1
1 个解决方案
#1
3
To group by section, and order by order you can do the following:
要按部分分组，并按订单排序，您可以执行以下操作：
items.sort_by(&:order).group_by(&:section).to_a
# => [["part one", [item1, item3]], ["part two", [item2]]]
sort_by orders all the items according to the order attribute, while group_by groups them into a hash of arrays, each key is a different section. to_a turns the hash into an array.
sort_by根据order属性对所有项进行排序，而group_by将它们分组为数组的散列，每个键是不同的部分。 to_a将哈希转换为数组。
If you want to keep the order of the section list, you can use it to define the order instead of to_a:
如果要保持部分列表的顺序，可以使用它来定义顺序而不是to_a：
grouped = items.sort_by(&:order).group_by(&:section)
# => { "part one" => [item1, item3], "part two" => [item2] }
sorted = sections.zip(sections.map { |s| grouped[s] })
# => [["part one", [item1, item3]], ["part two", [item2]]]
#1
3
To group by section, and order by order you can do the following:
要按部分分组，并按订单排序，您可以执行以下操作：
items.sort_by(&:order).group_by(&:section).to_a
# => [["part one", [item1, item3]], ["part two", [item2]]]
sort_by orders all the items according to the order attribute, while group_by groups them into a hash of arrays, each key is a different section. to_a turns the hash into an array.
sort_by根据order属性对所有项进行排序，而group_by将它们分组为数组的散列，每个键是不同的部分。 to_a将哈希转换为数组。
If you want to keep the order of the section list, you can use it to define the order instead of to_a:
如果要保持部分列表的顺序，可以使用它来定义顺序而不是to_a：
grouped = items.sort_by(&:order).group_by(&:section)
# => { "part one" => [item1, item3], "part two" => [item2] }
sorted = sections.zip(sections.map { |s| grouped[s] })
# => [["part one", [item1, item3]], ["part two", [item2]]]