[]=

Attribute AssignmentâAssigns to the instance variable named by symbol or fixnum the value obj and returns it. Will raise a NameError if the named variable does not exist, or an IndexError if the index is out of range.

Customer = Struct.new(:name, :address, :zip)
joe = Customer.new("Joe Smith", "123 Maple, Anytown NC", 12345)

joe["name"] = "Luke"
joe[:zip]   = "90210"

joe.name   #=> "Luke"
joe.zip    #=> "90210"