I have a multidimensional array in ruby like this one:
a = [[1, 2, 3], [4, 5, 6], [7, 8, 9]]
How do I add "1" to each element. For instance, I want to end up with something like this:
a = [[2, 3, 4], [5, 6, 7], [8, 9, 10]]
Thanks in advance!
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3 Answers
There might be a slightly more clever one liner but this is fairly clear.
a.map { |ar| ar.map { |e| e + 1 } }
8 Comments
Anthony Alberto
a.map { |ar| ar.map(&:next) } to avoid opening two blocks :)
sunnyrjuneja
Thanks, I had been sitting in irb for a few minutes trying to figure it out. Is it possible to do it without declaring
|ar|?Anthony Alberto
That's what I was thinking about, but we'd need to declare a method on
Array that takes each elements and adds 1 to them since there's nothing like that in the standard librarysunnyrjuneja
Is it not possible to do something like
a.map(&:map) and somehow pass &next to that?Anthony Alberto
I didn't know how it's called until I read a comment here : stackoverflow.com/questions/1217088/…. Apparently code
pretzel colon ... also there's a full explanation of how the magick works in it, a good read |
Just for fun :
class Array
def increment
map(&:next)
end
end
#Tada!
a.map(&:increment)
Comments
a.map { |xs| xs.map(&:succ) }
#=> [[2, 3, 4], [5, 6, 7], [8, 9, 10]]
