Hash in Ruby

Defining hash in Ruby

To define a hash in a Ruby program, we need to use curly brackets. Remember that we use square brackets for arrays:

$ pry
> obj = {}
...
> obj.class
Hash < Object

We should not name the variable hash because it is a reserved language keyword, but we can enter it into the REPL and see what happens. That’s why the authors usually use obj (object) orhh(double “h” indicates it’s more than just a variable).

Programmers say that the hash is key-value storage, where each key is assigned a value. For example, the key is ball, a string, and the value is the physical object ball itself. The hash is often called a ...