CODEWITHSUNDEEP
ruby-on-railsruby
prodigerati
prodigerati

Reputation: 607

Ruby increment string "0001" to use in .each

I would like to figure out how to increment a string "0001" inside of a .each ruby on rails model. I'm trying to use the number 0001 to put in a file path for active storage to import a pdf file.

The pdf file is exported from another program that auto increments the file name 0001_file.pdf and I have no way of changing that process.

I tried "0000".next but the number remains the same "0001".

    items.each do |f|
      num = "0000".next
      f.doc.attach(io: File.open("file/path/#{num}_file.pdf"), filename: "#{num}_file.pdf",   content_type: "application/pdf")
    end

What is the best way to save the string e.g. "0002" outside of the .each so it can be used to increment for the next iteration?

0001_file.pdf  
0002_file.pdf  
0003_file.pdf  
0004_file.pdf

Upvotes: 0

Views: 265

Answers (3)

Mayur Kambariya
Mayur Kambariya

Reputation: 107

Just add 0 and check the example below. 0001, 0010, 9999, 0919

 items.each_with_index do |f, index|
      num = sprintf '%04d', index + 1
      f.doc.attach(io: File.open("file/path/#{num}_file.pdf"), filename: "#{num}_file.pdf",   content_type: "application/pdf")
end

[1,2,3,4].each_with_index do |i, index|
    fileName = sprintf '%04d', index + 1
    puts fileName
end

Upvotes: 1

Kasi Raj R
Kasi Raj R

Reputation: 186

If the number of digits is less than four it will add leading zeros to make it 4 digits.

n = 4
file_num = 1
items.each do |f|
      num = file_num.to_s.rjust(n, '0')
      f.doc.attach(io: File.open("file/path/#{num}_file.pdf"), filename: "#{num}_file.pdf",   content_type: "application/pdf")
      file_num += 1
    end

1 will be 0001, 12 will be 0012

Upvotes: 2

Arvind singh
Arvind singh

Reputation: 1392

May be it isn't a best way but for workaround you can do like this

val = "000"
items.each.with_index(1) do |f, index|
  num = val + index.to_s
  f.doc.attach(io: File.open("file/path/#{num}_file.pdf"), filename: "#{num}_file.pdf",   content_type: "application/pdf")
end

This should result incremented value of num in each iteration like this 0001, 0002, 0003

Upvotes: -1

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