I have code:

  def make_all_thumbs(source)
    sizes = ['1000','1100','1200','800','600']
    threads = []
    sizes.each do |s|
      threads << Thread.new(s) {
        create_thumbnail(source+'.png', source+'-'+s+'.png', s)
      }
    end
  end

what does << mean?

ruby arrays operators
Edit
Report