The Ruby hash tutorial

For complex collections, the hash data structure is a powerful tool in Ruby programs. Hashes are key/value-based and let you access data elements with more than a pure index, such as with arrays. Though we've briefly touched on hashes in the previous lessons, I want to give you a firm understanding of what hashes are and how they can be used.

Essentially, a hash is a key/value pair collection. In an array, each element is a single item such as a number or word whereas in a hash, each element has two items, and includes a value and a key associated with it.

Sometimes, the value itself can be another collection like an array or a hash.

The hash code example

Let's start by creating a hash:

positions = { 
                first_base: "Chris Carter", 
                second_base: "Jose Altuve", 
                short_stop: "Carlos Correa" 
            } 

When you run this code, you can see the hash, where the keys are mapped to their respective values:

In the written code, I placed...