Refer to anonymous array within each/block

Question

I have the following in Ruby:

arr = [1, 2]
arr.each{|n| arr << n unless n > 2_000}

Is there any way to reference my array from within the block if I define it anonymously?

[1,2].each{|n| self << n unless n > 2_000}

Or something? I'm guessing not because I can't think of a way that I would reference it.

1) no, you can't. 2) **DO NOT** modify collection you're iterating. — Sergio Tulentsev, Mar 14 '14 at 04:02
@Sergio Tulentsev, 1) you can always write your own iterator that passes `self` as a parameter to given block 2) was Matz wrong by adding map!, flatten! etc to ruby? ps. no offense, just a discussion :) — trushkevich, Mar 14 '14 at 06:42
@trushkevich: http://en.wikipedia.org/wiki/Quod_licet_Iovi,_non_licet_bovi, I guess :) — Sergio Tulentsev, Mar 14 '14 at 06:58

score 1 · Answer 1 · answered Mar 14 '14 at 04:10

1

Changing the array when you are iterating it may cause infinite loop.

You could do below:

arr = [1, 2]
arr += arr.select { |n| n <= 2000 }

answered Mar 14 '14 at 04:10

xdazz

Bummer, that ruins my Project Euler fibonnaci solution: `arr.each{|x| arr << arr[-1] + fib[-2] unless x > 4_000_000 }.select{|n| n % 2 == 0}.reduce(:+)` – diplosaurus Mar 14 '14 at 04:29

score 1 · Accepted Answer · edited May 23 '17 at 11:49

1

here are similar (although outdated) questions:

also you could create a one-liner this way:

(arr = [1, 2]).each{|n| arr << n unless n > 2_000}

edited May 23 '17 at 11:49

Community

answered Mar 14 '14 at 06:32

trushkevich

score 0 · Answer 3 · answered Mar 14 '14 at 04:54

0

[].tap { |e| e.concat([1,2,20000].select { |n| n <= 2000 })

answered Mar 14 '14 at 04:54

Sharang Dashputre

3 Answers3