Array is a top-level Ruby conversion method that returns an array representation of its argument. For an ordinary string, it wraps the string as one element. section 9.2.1
Converting a string
Array("A string") returns ["A string"]. If the string is given a to_a method that splits it into characters, Array(string) instead returns ["A", " ", "s", "t", "r", "i", "n", "g"]. section 9.2.1
>> string = "A string"
=> "A string"
>> string.respond_to?(:to_ary)
=> false
>> string.respond_to?(:to_a)
=> false
>> Array(string) 1
=> ["A string"]
>> def string.to_a 2
>> split(//)
>> end
=> nil
>> Array(string)
=> ["A", " ", "s", "t", "r", "i", "n", "g"]
Compare the default conversion with conversion after defining to_a on the string. section 9.2.1
Array belongs alongside Array.new, literal arrays, and %w or %i notation as one of Ruby’s ways to create arrays, but its distinctive role is converting an existing argument. section 9.2.1
