Consecutive join operations on an Array in a single line of code

Question

I want to take a list of links and split them with alternating joins.

Here's what I have:

ruby-1.9.2-p290 :011 > tmp = [1,2,3,4,5,6].map(&:to_s)
 => ["1", "2", "3", "4", "5", "6"] 
ruby-1.9.2-p290 :012 > tmp2 = []
 => [] 
ruby-1.9.2-p290 :013 > tmp.each_slice(2) {|a| tmp2 << a.join("\t")}
 => nil 
ruby-1.9.2-p290 :014 > tmp2.join("<br\>")
 => "1\t2<br>3\t4<br>5\t6"

Is there a way to do this in a single line? I know I can do it with a Proc or a block call, but I am hoping for something cleaner. It seems like there is always some Array or Enumerable method I've yet to learn about, but I haven't found anything yet.

Ha, I don't, but I was trying to see if I could get an array out of it... and I didn't clean it out of the code. I'll correct this example. — Ryanmt
– Ryanmt, Commented Oct 18, 2011 at 23:08

Andrew Grimm · Accepted Answer · 2011-10-19 00:39:13Z

3

You can use map after each_slice, rather than using <<:

[1,2,3,4,5,6].each_slice(2).map {|a| a.join("\t")}.join("<br\>")

edited Oct 19, 2011 at 0:39

answered Oct 18, 2011 at 23:08

Andrew Grimm

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2 Comments

Ryanmt Over a year ago

Oh ruby... So beautiful. I was close. Thanks!

Roland Mai Over a year ago

You were 30s faster. Didn't see your answer till I posted mine.

Roland Mai · Accepted Answer · 2011-10-18 23:09:51Z

2

One liner:

[1,2,3,4,5,6].each_slice(2).map{|d| d.join("\t")}.join("<br/>")

answered Oct 18, 2011 at 23:09

Roland Mai

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2 Comments

Andrew Grimm Over a year ago

We probably don't need the .map(&:to_s) bit.

Roland Mai Over a year ago

@AndrewGrimm Thanks for catching that. :)

Batkins · Accepted Answer · 2011-10-18 23:10:53Z

0

tmp = [1,2,3,4,5,6].map(&:to_s)
tmp.map { |i| i.to_i % 2 == 1 ? "#{i}\t" : "#{i}<br>" }.to_s

answered Oct 18, 2011 at 23:10

Batkins

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2 Comments

Andrew Grimm Over a year ago

This puts "\t" after 6, which isn't wanted.

Batkins Over a year ago

Well you did say alternating. Just figured I'd give it a shot. : )

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