How do I print the line number of each line in a string?

Question

If I have a string within c1, I can print it in a line by doing:

c1.each_line do |line|
  puts line
end

I want to give the number of each line with each line like this:

c1.each_with_index  do |line, index|
  puts "#{index} #{line}"
end

But that doesn't work on a string.

I tried using $.. When I do that in the above iterator like so:

puts #{$.} #{line}

it prints the line number for the last line on each line.

I also tried using lineno, but that seems to work only when I load a file, and not when I use a string.

How do I print or access the line number for each line on a string?

Not what you asked for but you may be interested nonetheless, if you ever wanted all the lines in a file (the one you're actually in) you can add this to your script: p File.new(__FILE__).each.with_index { |l,i| puts "line #{i+1}: #{l}" };''. Try it out. — Sagar Pandya
– Sagar Pandya, Commented Jul 31, 2016 at 13:35

marcamillion · Accepted Answer · 2016-07-31 13:28:39Z

35

Slightly modifying your code, try this:

c1.each_line.with_index do |line, index|
   puts "line: #{index+1}: #{line}"
end

This uses with with_index method in Enumerable.

edited Jul 31, 2016 at 13:28

marcamillion

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answered Jul 31, 2016 at 13:08

Sagar Pandya

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1 Comment

marcamillion Over a year ago

This is awesome. Never knew about the with_index method on Enumerable. I learned something today! Thanks much meng!

Aetherus · Accepted Answer · 2016-07-31 13:20:32Z

8

Slightly modifying @sagarpandya82's code:

c1.each_line.with_index(1) do |line, index|
  puts "line: #{index}: #{line}"
end

answered Jul 31, 2016 at 13:20

Aetherus

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1 Comment

marcamillion Over a year ago

This is clever. Thanks for this modification.

Cary Swoveland · Accepted Answer · 2016-07-31 18:47:32Z

3

c1 = "Hey diddle diddle,\nthe cat and the fiddle,\nthe cow jumped\nover the moon.\n"

n = 1.step
  #=> #<Enumerator: 1:step> 
c1.each_line { |line| puts "line: #{n.next}: #{line}" }
  # line: 1: Hey diddle diddle,
  # line: 2: the cat and the fiddle,
  # line: 3: the cow jumped
  # line: 4: over the moon.

edited Jul 31, 2016 at 18:47

answered Jul 31, 2016 at 18:41

Cary Swoveland

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