Difference between '..' (double-dot) and '…' (triple-dot) in range generation?

Question

I\'ve just started learning Ruby and Ruby on Rails and came across validation code that uses ranges:

validates_inclusion_of :age, :in => 21..99
validates_         


        

Answer 1

The API docs now describe this behaviour:

Ranges constructed using .. run from the beginning to the end inclusively. Those created using ... exclude the end value.

-- http://ruby-doc.org/core-2.1.3/Range.html

In other words:

2.1.3 :001 > ('a'...'d').to_a
 => ["a", "b", "c"] 
2.1.3 :002 > ('a'..'d').to_a
 => ["a", "b", "c", "d"]