How do I modify the second element in a nested array, within an array, alone? - Ruby

Question

So say I have a 2D array like this:

list = [["auburn", "http://auburn.craigslist.org"], ["birmingham", "http://bham.craigslist.org"], ["dothan", "http://dothan.craigslist.org"]]

I would like it to look like this:

list = [["auburn", "http://auburn.craigslist.org/web/"], ["birmingham", "http://bham.craigslist.org/web/"], ["dothan", "http://dothan.craigslist.org/web/"]]

So I have just modified the second element within each nested array.

How do I do that in Ruby?

Thanks.

intellidiot · Accepted Answer · 2012-05-15 10:27:44Z

3

Try this

list.map!{|f,l| [f, l + "/web/"]}

answered May 15, 2012 at 10:27

intellidiot

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2 Comments

marcamillion Over a year ago

This works...but another thing I am trying to do is to add another to each list element with another url modified with the ending /bk/ for instance. So list would then be [0] = text, [1] = url.com/web/,[2] = url.com/bk/. How can I do that here?

intellidiot Over a year ago

This should do: list.map!{|f,l| [f, l + "/web/", l + "/bk/"]}

cheetah · Accepted Answer · 2012-05-15 23:49:30Z

1

list.map! { |elem| [elem[0], elem[1] << '/web/'] }

edited May 15, 2012 at 23:49

answered May 15, 2012 at 10:04

cheetah

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2 Comments

marcamillion Over a year ago

This works wonders...one question...so basically I want to capture each URL in elem[1] before it is modified...which I will then use as the base for another URL in elem[2]. How do I do that? I tried setting a local variable to be elem[1] before I append /web/ to it, but it still gives me the modified URL for elem[2] instead of the pre-modified one. i.e. I am getting url.com/web/ instead of just url.com.

steenslag Over a year ago

This creates a new list AND modifies the existing one. If you want to modify the (strings in the) existing list, don't use map, just use each.

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