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Feature #12447

Updated by mrkn (Kenta Murata) 11 months ago

I sometimes want to extract digits of place-value notation of integer numbers.

For example:

```

12345.digits #=> [5, 4, 3, 2, 1]
12345.digits(100) #=> [45, 23, 1]
```

One typical use case is calculating checksum digit.
I found some code extracting digits by the way like `int.to_s.chars.map(&:to_i)`.

- https://github.com/joeljunstrom/ruby_luhn/blob/master/lib/luhn.rb#L43
- https://github.com/elitwin/check_digit/blob/master/lib/check_digit/damm.rb#L28
- https://github.com/elitwin/check_digit/blob/master/lib/check_digit/luhn.rb#L14
- https://github.com/elitwin/check_digit/blob/master/lib/check_digit/verhoeff.rb#L42

Introducing Integer#digits can reduce needless string allocation in such cases.

The patch was pushed into the repository in github.
https://github.com/mrkn/ruby/commit/5dce32d

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