Bird
0
0

What will be the output of this Ruby code?

medium📝 Predict Output Q13 of 15
Ruby - Operators and Expressions
What will be the output of this Ruby code?
a = nil
b = 20
a ||= 10
b ||= 30
puts a
puts b
A10\n30
Bnil\n30
Cnil\n20
D10\n20
Step-by-Step Solution
Solution:

  1. Step 1: Evaluate a ||= 10 when a is nil

    Since a is nil, a ||= 10 assigns 10 to a.

  2. Step 2: Evaluate b ||= 30 when b is 20

    Since b is already 20 (truthy), b ||= 30 does not change b.

  3. Final Answer:

    10 20 -> Option D

  4. Quick Check:

    nil replaced, truthy kept = 10 and 20 [OK]
Quick Trick: ||= changes only nil or false variables [OK]
Common Mistakes:
  • Assuming b changes to 30
  • Thinking nil stays nil after ||= 10
  • Mixing up output order

Want More Practice?

15+ quiz questions · All difficulty levels · Free

Free Signup - Practice All Questions
More Ruby Quizzes
Arrays - Array methods (length, include?, flatten) - Quiz 2easy Control Flow - Ternary operator usage - Quiz 13medium Hashes - Hash methods (keys, values, each) - Quiz 12easy Methods - Method naming conventions (? and ! suffixes) - Quiz 3easy Operators and Expressions - Spaceship operator (<=>) - Quiz 2easy String Operations - String concatenation and << - Quiz 12easy String Operations - String methods (upcase, downcase, strip) - Quiz 14medium String Operations - Gsub and sub for replacement - Quiz 7medium String Operations - String methods (upcase, downcase, strip) - Quiz 7medium Variables and Data Types - Nil as the absence of value - Quiz 4medium