[Solved] What will be the output of this Ruby code? class Person attr_writer :age def initialize(age) @age = age end def show_age @age end end p = Person.new(30) puts p.show_age p.age = 40 puts p.show_age | Ruby

Ruby - Classes and Objects

What will be the output of this Ruby code?

class Person
  attr_writer :age
  def initialize(age)
    @age = age
  end
  def show_age
    @age
  end
end

p = Person.new(30)
puts p.show_age
p.age = 40
puts p.show_age

A30\n40

B30\n30

CError: undefined method `age='

DError: undefined method `show_age'

Step-by-Step Solution

Solution:

Step 1: Understand attr_writer effect
attr_writer :age creates a setter method age=, but no getter method is created.
Step 2: Analyze method calls
p.show_age returns @age which is 30 initially. Then p.age = 40 sets @age to 40. But p.show_age returns @age which is now 40.
Step 3: Check output
Actually, p.show_age is called twice, before and after setting age. So outputs are 30 then 40.
Final Answer:
30\n40 -> Option A
Quick Check:
attr_writer allows setting, show_age reads @age [OK]

Quick Trick: attr_writer only sets; custom getter needed [OK]

Common Mistakes:

Assuming attr_writer creates getter method
Expecting error on p.age= assignment
Confusing show_age method with attr_reader

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What will be the output of this Ruby code?

Step 1: Understand attr_writer effect

Step 2: Analyze method calls

Step 3: Check output

Final Answer:

Quick Check:

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