In Ruby, when I call reverse method on an array, it doesn't reverse sort the array completely.
array = [5, 4, 9, 8, 7, 1, 2]
array.reverse # => [2, 1, 7, 8, 9, 4, 5]
I'm unable to understand what operation it's performing on the array.
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user513951
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user3430287
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2http://www.ruby-doc.org/core-2.1.5/Array.html#method-i-reverse – Chris Heald Nov 18 '14 at 05:46
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@ChrisHeald I was there in first place, but that gave me a very short description of the method, too short to grasp it. Therefore, I asked it here! – user3430287 Nov 18 '14 at 05:48
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1`reverse` does no sorting, it just reverses the order of the elements in the list. – jayelm Nov 18 '14 at 05:50
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@JesseMu Got it. It is so easy thing, and I wasn't understanding it at all. – user3430287 Nov 18 '14 at 06:07
2 Answers
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> array
=> [5, 4, 9, 8, 7, 1, 2]
> array.sort.reverse # it will sort the array by value in descending order
=> [9, 8, 7, 5, 4, 2, 1]
Note:
- sort : Returns a new array created by sorting self.
- reverse : Returns a new array containing self‘s elements in reverse order.
See how it works:
> array.reverse # it will reverse the array by indexing
=> [2, 1, 7, 8, 9, 4, 5]
> array.sort # it will sort the array by value in ascending order
=> [1, 2, 4, 5, 7, 8, 9]
Hetal Khunti
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Array#reverse reverses the order of an array, but does not sort the array in reverse order.
array = [1,5,7,3]
array.reverse
=> [3,7,5,1]
If you want to sort an array in reverse order, you could try this
array.sort_by{|a|array.max - a}
Darkmouse
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