[Solved] What will be the output of this Ruby code? thread = Thread.new { 3.times { |i| puts i; sleep 0.1 } } thread.join puts "Done" | Ruby

Ruby - Concurrent Programming

What will be the output of this Ruby code?

thread = Thread.new { 3.times { |i| puts i; sleep 0.1 } }
thread.join
puts "Done"

A0 1 2 Done

BDone 0 1 2

C0 1 2 Done

DDone

Step-by-Step Solution

Solution:

Step 1: Understand thread execution and join
The thread prints numbers 0, 1, 2 with pauses. The main thread waits for it to finish because of join.
Step 2: Determine output order
Numbers 0, 1, 2 print first, then "Done" prints after the thread finishes.
Final Answer:
0\n1\n2\nDone -> Option C
Quick Check:
Thread.join waits, so output order is numbers then Done [OK]

Quick Trick: join waits for thread, so output order is thread then main [OK]

Common Mistakes:

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