return the size of an array with either the size or length method


months = Array.new(12)
months.size # => 12

# or:

months.length # => 12

1.	Creating Arrays with the new class method:
2.	Array.new creates an empty array, represented as [], named months.
3.	set the size of an array (the number of elements in an array)
4.	assign an object (such as a string) to each element in the array
5.	Creating an Array with a Block
6.	takes a range as an argument to create an array of digits.
7.	if you submit a set of strings, Array accepts them as a single, concatenated element.
8.	A basic array with []
9.	To create an array, you use the [] operator
10.	store text strings as well as numbers in arrays
11.	Creates a array with the Array class's new method: array2 = Array.new
12.	Arrays don't need to be set up with predefined entries or have elements allocated manually.
13.	Examples of the methods provided by Enumerable
14.	Define an array of strings is with the %w notation.

return the size of an array with either the size or length method : Array Creation « Array « Ruby