The Book of Ruby

Chapter 4. Arrays and Hashes

Up to now, you’ve generally been using objects one at a time. In this chapter, you’ll find out how to create a list of objects. You’ll start by looking at the most common type of list structure: an array.

Arrays

An array is a sequential collection of items in which each item can be indexed. In Ruby (unlike many other languages), a single array can contain items of mixed data types such as strings, integers, and floats or even a method call that returns some value. For example, the final element in a1 shown here calls my method, array_length, which returns the length of the array, a0:

array0.rb

def array_length( anArray ) ...