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[英]Hash with 3 different keys each pointing to an array of instances. How do I sort the arrays by id?
[英]How can I sort this array of arrays by the second value in each array?
我有以下數組:
[[1, 2], [44, 1], [18395, 3]]
我通過使用此代碼獲得的:
current_user.friends_products.where("units.primary_image_id IS NOT NULL").group_by{|u| u.creator_id}.map {|k,v| [k, v.length]}
我想按每個數組的第二個值從最大到最小排序數組。 所以,這就是我想要實現的目標:
[[18395, 3], [1, 2], [44, 1]]
使用#sort_by和第二個元素降序:
x = [[1, 2], [44, 1], [18395, 3]]
x.sort_by { |a, b| -b }
#=> [[18395, 3], [1, 2], [44, 1]]
[[1, 2], [44, 1], [18395, 3]].sort_by(&:last).reverse
您可以使用此Array#sort
塊:
[[1, 2], [44, 1], [18395, 3]].sort { |a, b| b[1] <=> a[1] }
# => [[18395, 3], [1, 2], [44, 1]]
arr =[[1, 2], [44, 1], [18395, 3]]
arr.sort_by{|x,y|y}.reverse
# => [[18395, 3], [1, 2], [44, 1]]
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