# Array manipulation

Hi Folks,

I have a general newbie type question
Say I have a 2D array that I obtained from an external program:

array = [[“a”, “b”, “”, “c”, “5”], [“d”, “e”, “f”, “9.0”, “7”, “g”, “”,
“”, “”], ["", “h”, “5”, “”, “”]]

Is there a way to remove just the last two empty strings ("") in the
last element, so the array will look like this:

array = [[“a”, “b”, “”, “c”, “5”], [“d”, “e”, “f”, “9.0”, “7”, “g”, “”,
“”, “”], ["", “h”, “5”]]

I’ve looked at array.compact, but this removes all of the empty
strings(""), plus I’d have to flatten the array to 1D, which is no good.

Analogy A. wrote:

Hi Folks,

I have a general newbie type question
Say I have a 2D array that I obtained from an external program:

array = [[“a”, “b”, “”, “c”, “5”], [“d”, “e”, “f”, “9.0”, “7”, “g”, “”,
“”, “”], ["", “h”, “5”, “”, “”]]

Is there a way to remove just the last two empty strings ("") in the
last element, so the array will look like this:

array = [[“a”, “b”, “”, “c”, “5”], [“d”, “e”, “f”, “9.0”, “7”, “g”, “”,
“”, “”], ["", “h”, “5”]]

you can use array[2][3,2] = nil to delete the last 2 elements
and use flatten to get a new array

On 9/25/07, Analogy A. [email protected] wrote:

last element, so the array will look like this:

2.times{ array.last.pop }

but is this really what you want? I mean are you not up to something
more general?
for example:
2.times{ array.last.pop if array.last.empty? }
do you see what I mean?

Cheers
Robert

Say I have a 2D array that I obtained from an external program:
“7”, “g”, “”,
“”, “”], ["", “h”, “5”]]

## I’ve looked at array.compact, but this removes all of the empty strings(""), plus I’d have to flatten the array to 1D, which is no good. Thanks in advance!

Posted via http://www.ruby-forum.com/.

If I understand you right and all you want to do is to remove empty
strings
from the end of the last array in an array of arrays, this should
suffice:

irb(main):001:0> a = [[“a”, “b”, “”, “c”, “5”], [“d”, “e”, “f”, “9.0”,
“7”,
“g”, “”, “”, “”], ["", “h”, “5”, “”, “”]]
=> [[“a”, “b”, “”, “c”, “5”], [“d”, “e”, “f”, “9.0”, “7”, “g”, “”, “”,
“”],
["", “h”, “5”, “”, “”]]
irb(main):002:0> while a.last.last == “” do
irb(main):003:1* a.last.pop
irb(main):004:1> end
=> nil
irb(main):005:0> a
=> [[“a”, “b”, “”, “c”, “5”], [“d”, “e”, “f”, “9.0”, “7”, “g”, “”, “”,
“”],
["", “h”, “5”]]
irb(main):006:0>

HTH,

Felix

On Tue, 2007-09-25 at 23:36 +0900, Analogy A. wrote:

Hi Folks,

I have a general newbie type question
Say I have a 2D array that I obtained from an external program:

array = [[“a”, “b”, “”, “c”, “5”], [“d”, “e”, “f”, “9.0”, “7”, “g”, “”,
“”, “”], ["", “h”, “5”, “”, “”]]

this any good?
i’d assumed you just wanted to get rid of the two empty strings as
they’re duplicates…

irb(main):015:0> arr = [[‘paul’,‘fox’,’’,’’],[‘testing’,‘123’,’’,’’]]
=> [[“paul”, “fox”, “”, “”], [“testing”, “123”, “”, “”]]
irb(main):016:0> arr.map{|a| pp a.uniq}
[“paul”, “fox”, “”]
[“testing”, “123”, “”]
=> [nil, nil]
irb(main):017:0>