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I have the following array [12,16,5,9,11,5,4] it prints: 12,16,5,9,11,5,4.
I want it to print: 4,5,11,9,5,16,12
When I did array.reverse it printed:
4,5,11,9,5,61,21
It reversed individual numbers - any idea how I can stop that?
676
reverse() The reverse() method reverses an array in place and returns the reference to the same array, the first array element now becoming the last, and the last array element becoming the first.
The Ruby sort method works by comparing elements of a collection using their <=> operator (more about that in a second), using the quicksort algorithm. You can also pass it an optional block if you want to do some custom sorting. The block receives two parameters for you to specify how they should be compared.
a = [12,16,5,9,11,5,4]
# => [12, 16, 5, 9, 11, 5, 4]
a.reverse
# => [4, 5, 11, 9, 5, 16, 12]
I'm not seeing what you're seeing.
Edit: Expanding on what Ben noticed, you may be reversing a string.
"12,16,5,9,11,5,4".reverse
# => "4,5,11,9,5,61,21"
If you have to reverse a string in that manner, you should do something like the following:
"12,16,5,9,11,5,4".split(",").reverse.join(",")
# => "4,5,11,9,5,16,12"
Sounds like your array is actually a String
26
Are you trying to reverse the list in place? If so then do:
>> arr = [12,16,5,9,11,5,4]
=> [12, 16, 5, 9, 11, 5, 4]
>> arr.reverse!
=> [4, 5, 11, 9, 5, 16, 12]
>> arr
=> [4, 5, 11, 9, 5, 16, 12]
Otherwise:
>> arr_rev=arr.reverse
=> [4, 5, 11, 9, 5, 16, 12]
>> arr_rev
=> [4, 5, 11, 9, 5, 16, 12]
If your array is an actual string, try this:
"12,16,5,9,11,5,4".split(',').reverse
Hope that solves your problem!
40
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