ruby-delete_at

a = [5,1,4,2,3]

a.delete_at(0) #=> 5
p a #=> [1, 4, 2, 3]

a.delete_at(1) #=> 4
p a #=> [1, 2, 3]

http://www.namaraii.com/rubytips/?%C7%DB%CE%F3