A ticket can hold a venue, date, and price in instance variables. Accessor methods give other code a way to read or change that state: a reader returns a value, while a writer accepts a new one. Ruby convention names a reader after the attribute, such as `venue`, rather than `get_venue`. section 3.2.1 section 3.3
Reading and changing a ticket’s price
```ruby class Ticket def initialize(venue, date) @venue = venue @date = date end def price @price end def price=(amount) @price = amount end end ticket = Ticket.new("Town Hall", "2025-11-12") ticket.price = 63.00 ticket.price # => 63.0 ``` The reader returns `@price` because it is the method’s last expression. The writer stores its argument in that instance variable. section 3.2.1 section 3.3.1
`ticket.price = 63.00` looks like assignment, but it calls the method `price=` on `ticket` with `63.00` as its argument. The same call can be written `ticket.price=(63.00)`. This assignment-like syntax is available to methods whose names end in `=`; it does not make `ticket.price` a variable. section 3.3.1 section 3.3.2
A writer need not blindly store its argument. A `price=` method can reject a price with extra decimal places, and a `year=` method can convert a two-digit year into a four-digit one. The assignment-like spelling does not guarantee sensible behavior: the method’s implementation determines what happens. section 3.3.3
For straightforward accessors, `attr_reader :venue, :date` creates readers, `attr_writer :price` creates a writer, and `attr_accessor :price` creates both a reader and a writer. Write the methods out when access needs custom behavior. Like other instance methods, accessors can also be inherited by subclasses. section 3.4.1 section 3.5
