Ruby’s Comparable

Every comparable methods in Ruby are implemented with <=>.

“Is equal to” (==), “not equal to” (!=), “less than” (<) and “greater than” (>) operators and symbols are pretty straightforward.

One method I often forget is the Comparable#between: this useful method is called with two parameters: a minimum and a maximum. It returns a Boolean, true or false, depending on the result of the comparison between the object it is called upon and the two parameters.

From the doc:

3.between?(1, 5)               #=> true
6.between?(1, 5)               #=> false
'cat'.between?('ant', 'dog')   #=> true
'gnu'.between?('ant', 'dog')   #=> false