How to compare versions in Ruby?

Question

How to write a piece of code to compare some versions strings and get the newest?

For example strings like: \'0.1\', \'0.2.1\', \'0.44\'.

Answer 1

If you need to check pessimistic version constraints, you can use Gem::Dependency like this:

Gem::Dependency.new('', '~> 1.4.5').match?('', '1.4.6beta4')

Answer 2

Gem::Version is the easy way to go here:

%w<0.1 0.2.1 0.44>.map {|v| Gem::Version.new v}.max.to_s
=> "0.44"