Ostruct in

About Ostruct

Ruby comes with a Standard Library (often shortened to "stdlib") - a collection of classes for working with things such as dates, json, and networking. It also provides some useful functionality for making your code easier to work with.

OpenStruct is part of the Standard Library and allows you to easily create an object from a Hash. Rather than having to access using Hash keys, OpenStruct instead allows us to use methods to access and set values.

When using classes from the Standard Library, or any other library, you need to require that class using the require method.

require 'ostruct'

attributes = { name: "Jeremy Walker", age: 21, location: "Nomadic" }
person = OpenStruct.new(attributes)

person.name
#=> Jeremy Walker

person.location
#=> Nomadic

# Update the age
person.age = 35

# It sets correctly
person.age
#=> 35

One bonus advantage of this is that you can take advantage of a shortcut when using block syntax. In situations where a block calls a single method, you can replace the block with &: followed by the method name. For example, these two lines are synonymous:

people.sum { |person| person.age }
people.sum(&:age)