How to sort an array based on its transformation
I would like to sort an array:
initial_array = ['23', '504', '2']
based on the sum of each element's digits. Transformed array is:
[5, 9, 2]
Sorting the array by the mapping:
chars.map(&:to_i).reduce(:+)
gives the sorted transformed array:
sorted_transformed_array # => [2, 5, 9]
The sorted initial array is:
['2', '23', '504']
How do I sort initial_array based on sorted_transformed_array? Is there a method that does this?
What is the difference from the sort_by! method?
ruby sorting
edited Jan 21 at 5:25
sawa
131k29204301
asked Jan 20 at 10:10
Ckn07Ckn07
61
add a comment |
I would like to sort an array:
initial_array = ['23', '504', '2']
based on the sum of each element's digits. Transformed array is:
[5, 9, 2]
Sorting the array by the mapping:
chars.map(&:to_i).reduce(:+)
gives the sorted transformed array:
sorted_transformed_array # => [2, 5, 9]
The sorted initial array is:
['2', '23', '504']
How do I sort initial_array based on sorted_transformed_array? Is there a method that does this?
What is the difference from the sort_by! method?
ruby sorting
edited Jan 21 at 5:25
sawa
131k29204301
asked Jan 20 at 10:10
Ckn07Ckn07
61
add a comment |
I would like to sort an array:
initial_array = ['23', '504', '2']
based on the sum of each element's digits. Transformed array is:
[5, 9, 2]
Sorting the array by the mapping:
chars.map(&:to_i).reduce(:+)
gives the sorted transformed array:
sorted_transformed_array # => [2, 5, 9]
The sorted initial array is:
['2', '23', '504']
How do I sort initial_array based on sorted_transformed_array? Is there a method that does this?
What is the difference from the sort_by! method?
ruby sorting
edited Jan 21 at 5:25
sawa
131k29204301
asked Jan 20 at 10:10
Ckn07Ckn07
61
I would like to sort an array:
initial_array = ['23', '504', '2']
based on the sum of each element's digits. Transformed array is:
[5, 9, 2]
Sorting the array by the mapping:
chars.map(&:to_i).reduce(:+)
gives the sorted transformed array:
sorted_transformed_array # => [2, 5, 9]
The sorted initial array is:
['2', '23', '504']
How do I sort initial_array based on sorted_transformed_array? Is there a method that does this?
What is the difference from the sort_by! method?
ruby sorting
ruby sorting
edited Jan 21 at 5:25
sawa
131k29204301
asked Jan 20 at 10:10
Ckn07Ckn07
61
edited Jan 21 at 5:25
sawa
131k29204301
asked Jan 20 at 10:10
Ckn07Ckn07
61
edited Jan 21 at 5:25
sawa
131k29204301
edited Jan 21 at 5:25
sawa
131k29204301
edited Jan 21 at 5:25
sawa
131k29204301
131k29204301
asked Jan 20 at 10:10
Ckn07Ckn07
61
asked Jan 20 at 10:10
Ckn07Ckn07
61
asked Jan 20 at 10:10
Ckn07Ckn07
61
61
add a comment |
add a comment |
1 Answer
1
active
oldest
votes
Use that transformation/calculation in combination with sort_by method
Before ruby 2.4
array.sort_by { |item| item.chars.map(&:to_i).reduce(0, :+) }
Since ruby 2.4
array.sort_by { |item| item.chars.map(&:to_i).sum }
answered Jan 20 at 10:23
UrsusUrsus
20.5k31530
Enumerable#sum:)
– Aleksei Matiushkin
Jan 20 at 10:25
1
Oritem.to_i.digits.sum
– Stefan
Jan 20 at 16:35
add a comment |
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1 Answer
1
active
oldest
votes
1 Answer
1
active
oldest
votes
active
oldest
votes
active
oldest
votes
Use that transformation/calculation in combination with sort_by method
Before ruby 2.4
array.sort_by { |item| item.chars.map(&:to_i).reduce(0, :+) }
Since ruby 2.4
array.sort_by { |item| item.chars.map(&:to_i).sum }
answered Jan 20 at 10:23
UrsusUrsus
20.5k31530
Enumerable#sum:)
– Aleksei Matiushkin
Jan 20 at 10:25
1
Oritem.to_i.digits.sum
– Stefan
Jan 20 at 16:35
add a comment |
Use that transformation/calculation in combination with sort_by method
Before ruby 2.4
array.sort_by { |item| item.chars.map(&:to_i).reduce(0, :+) }
Since ruby 2.4
array.sort_by { |item| item.chars.map(&:to_i).sum }
answered Jan 20 at 10:23
UrsusUrsus
20.5k31530
Enumerable#sum:)
– Aleksei Matiushkin
Jan 20 at 10:25
1
Oritem.to_i.digits.sum
– Stefan
Jan 20 at 16:35
add a comment |
Use that transformation/calculation in combination with sort_by method
Before ruby 2.4
array.sort_by { |item| item.chars.map(&:to_i).reduce(0, :+) }
Since ruby 2.4
array.sort_by { |item| item.chars.map(&:to_i).sum }
answered Jan 20 at 10:23
UrsusUrsus
20.5k31530
Use that transformation/calculation in combination with sort_by method
Before ruby 2.4
array.sort_by { |item| item.chars.map(&:to_i).reduce(0, :+) }
Since ruby 2.4
array.sort_by { |item| item.chars.map(&:to_i).sum }
answered Jan 20 at 10:23
UrsusUrsus
20.5k31530
edited Jan 20 at 10:45
answered Jan 20 at 10:23
UrsusUrsus
20.5k31530
answered Jan 20 at 10:23
UrsusUrsus
20.5k31530
answered Jan 20 at 10:23
UrsusUrsus
20.5k31530
20.5k31530
Enumerable#sum:)
– Aleksei Matiushkin
Jan 20 at 10:25
1
Oritem.to_i.digits.sum
– Stefan
Jan 20 at 16:35
add a comment |
Enumerable#sum:)
– Aleksei Matiushkin
Jan 20 at 10:25
1
Oritem.to_i.digits.sum
– Stefan
Jan 20 at 16:35
Enumerable#sum :)– Aleksei Matiushkin
Jan 20 at 10:25
Enumerable#sum :)– Aleksei Matiushkin
Jan 20 at 10:25
1
1
Or
item.to_i.digits.sum– Stefan
Jan 20 at 16:35
Or
item.to_i.digits.sum– Stefan
Jan 20 at 16:35
add a comment |
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