How can I output leading zeros in Ruby?

Question

I\'m outputting a set of numbered files from a Ruby script. The numbers come from incrementing a counter, but to make them sort nicely in the directory, I\'d like to use leading

Answer 1

Use String#next as the counter.

>> n = "000"
>> 3.times { puts "file_#{n.next!}" }
file_001
file_002
file_003

next is relatively 'clever', meaning you can even go for

>> n = "file_000"
>> 3.times { puts n.next! }
file_001
file_002
file_003