Add 0 padding to number in middle of string in ruby

Question

This may be a really simple regex but its one of those problems that have proven hard to google.

I have error codes coming back from a third party system. They are supposed to be in the format:

ZZZ##

where Z is Alpha and # is numeric. They are supposed to be 0 padded, but i'm finding that sometimes they come back

ZZZ#

without the 0 padding.

Anyone know how i could add the 0 padding so i can use the string as an index to a hash?

How many zeroes do you want to add? Just one?

Sergio Tulentsev
– Sergio Tulentsev

2012-04-30 23:55:07 +00:00
Commented Apr 30, 2012 at 23:55 — Sergio Tulentsev
– Sergio Tulentsev, Commented Apr 30, 2012 at 23:55
sorry ya. it should match that ZZZ## format

JoshReedSchramm
– JoshReedSchramm

2012-04-30 23:55:37 +00:00
Commented Apr 30, 2012 at 23:55 — JoshReedSchramm
– JoshReedSchramm, Commented Apr 30, 2012 at 23:55

Sergio Tulentsev · Accepted Answer · 2012-05-01 00:10:23Z

3

Here's my take:

def pad str
  number = str.scan(/\d+/).first
  str[number] = "%02d" % number.to_i
  str
end

6.times do |n|
  puts pad "ZZZ#{7 + n}"
end

# >> ZZZ07
# >> ZZZ08
# >> ZZZ09
# >> ZZZ10
# >> ZZZ11
# >> ZZZ12

Reading:

edited May 1, 2012 at 0:10

answered May 1, 2012 at 0:00

Sergio Tulentsev

231k43 gold badges381 silver badges373 bronze badges

Sign up to request clarification or add additional context in comments.

Comments

Phrogz · Accepted Answer · 2012-05-01 00:11:05Z

2

fixed = str.gsub /([a-z]{3})(\d)(?=\D|\z)/i, '\10\2'

That says:

Find three letters
- …followed by a digit
- …and make sure that then you see either a non-digit or the end of file
and replace with the three letters (\1), a zero (0), and then the digit (\2)

To pad to an arbitrary length, you could:

# Pad to six digits
fixed = str.gsub /([a-z]{3})(\d+)/i do
  "%s%06d" % [ $1, $2.to_i ]
end

edited May 1, 2012 at 0:11

answered May 1, 2012 at 0:04

Phrogz

304k115 gold badges669 silver badges758 bronze badges

1 Comment

Sergio Tulentsev Over a year ago

On SO you learn every day. :) Thank you, sir, for this neat trick with gsub and block :)

pguardiario · Accepted Answer · 2012-05-01 01:29:03Z

1

Here's mine:

"ZZZ7".gsub(/\d+/){|x| "%02d" % x}
=> "ZZZ07"

answered May 1, 2012 at 1:29

pguardiario

55.2k21 gold badges130 silver badges169 bronze badges

Comments

ashoda · Accepted Answer · 2012-05-01 00:55:40Z

0

There's probably a million ways to do this but here's another look.

str.gsub!(/[0-9]+/ , '0\0' ) if str.length < 5

answered May 1, 2012 at 0:55

ashoda

2,8801 gold badge16 silver badges9 bronze badges

Collectives™ on Stack Overflow

Add 0 padding to number in middle of string in ruby

4 Answers 4

Comments

1 Comment

Comments

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

4 Answers 4

Comments

1 Comment

Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Related