[Solved] What will be the output of the following Ruby code?class Parent @@value = 10 def self.value @@value end end class Child | Ruby

Ruby - Class Methods and Variables

What will be the output of the following Ruby code?

class Parent
  @@value = 10
  def self.value
    @@value
  end
end

class Child < Parent
  @@value = 20
end

puts Parent.value
puts Child.value

A10 20

B20 20

C10 10

DError: class variable redefinition

Step-by-Step Solution

Solution:

Step 1: Understand class variable sharing
@@value is shared between Parent and Child classes.
Step 2: Analyze assignment in Child
Child sets @@value to 20, which changes the shared variable for both classes.
Step 3: Check output of Parent.value and Child.value
Both calls return 20 because @@value is shared and last set to 20.
Final Answer:
20 20 -> Option B
Quick Check:
Shared @@value reflects last assignment [OK]

Quick Trick: Class variables shared, last assignment wins [OK]

Common Mistakes:

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