Ruby Monstas

Symbols

Symbols are like Strings, but different.

:coffee
:giraffe
:Tokyo

Wait, what? 😳

OK... Symbols are like stupid Strings. ^{[citation needed]}

movie = "Ghostbusters"
movie.reverse         # => "sretsubtsohG"
movie.include?("bus") # => true

movie = :Ghostbusters
movie.reverse         # => NoMethodError
movie.include?("bus") # => NoMethodError

But, why do they exist? 👩‍🎓

Under the hood of Ruby, Symbols have some advantages over Strings.

Those advantages are not significant at this stage of learning the language.

If you're interested in details consider reading this:
https://ruby-for-beginners.rubymonstas.org/built_in_classes/symbols.html

Where to use Symbols

We love using Symbols as keys in Hashes

movie = { :name => "Ghostbusters" }  # very good 👍

movie = { "name" => "Ghostbusters" } # less good 👎

Using Symbols as keys in Hashes

In Hashes, Ruby allows us to put the colon : at the end of a key and omit the =>

movie = { :name => "Ghostbusters" }  # very good 👍

movie = { name: "Ghostbusters" }     # amazing 👍👍👍

Using Symbols as keys in Hashes

Use Symbols to access the values again:

movie = { name: "The Grand Budapest Hotel" }

movie["name"]   # => nil
movie[:name]    # => "The Grand Budapest Hotel"

Summary / Recommendation

first_name = :Eileen  # Nay 👎
first_name = "Eileen" # Yay 👍

person = { "first_name" => "Eileen" } # Nay 👎
person = { first_name: "Eileen" }     # Yay 👍

Additional Resources

Ruby For Beginners: Symbols

What questions do you have?