What is wrong with this Ruby code that tries to use concurrency?

medium📝 Debug Q14 of 15

Ruby - Concurrent Programming

threads = []
i = 0
5.times do
  threads << Thread.new do
    puts i
  end
  i += 1
end
threads.each(&:join)

AThe code will cause a syntax error.

BThe variable i is shared and may cause unexpected output.

Cthreads.each(&:join) should be threads.join.

DThread.new is not the correct way to create threads.

Step-by-Step Solution

Solution:

Step 1: Analyze variable capture in threads
The block uses variable i from the loop, which may change before thread runs, causing unexpected output.
Step 2: Identify concurrency issue
Each thread may print the same or wrong i value because i is shared and changes quickly.
Final Answer:
The variable i is shared and may cause unexpected output. -> Option B
Quick Check:
Loop variable shared in threads causes bugs [OK]

Quick Trick: Loop variables shared in threads cause unexpected values [OK]

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