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

Ruby - Concurrent Programming

What will this Ruby code output?

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 to 2 with pauses, then main waits for thread to finish because of join.
Step 2: Determine output order
Numbers 0,1,2 print first, then 'Done' prints after thread finishes.
Final Answer:
0 1 2 Done -> Option A
Quick Check:
Thread.join waits for thread completion = Output order correct [OK]

Quick Trick: Thread.join waits for thread to finish before continuing [OK]

Common Mistakes:

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