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Ruby Ruby Modules Store Inventory Using Modules Extend and Include

Mateusz Leśniak
Mateusz Leśniak
4,762 Points

Creating instances array

Hi, at which point we are creating @instances array? We made a method inside Inventoryable module to conditionally assign empty array to @instances variable, but we are not calling this method. It is enough to push something inside instances and the array is created at the same time?

Christopher Phillips
Christopher Phillips
10,061 Points

Hi Mateusz,

The array is created here. Read it as "We create the instances array and it is given no value the first time it is accessed."

def instances
    @instances ||= []
end

We populated the instances array via the create method within the ClassMethods module:

def create(attributes)
    object = new(attributes)
    instances.push(object)
    return object
end

The create method is called via this code:

shirt1 = Shirt.create(name: "mtf", size: "L")