Retry for reattempting in Ruby - Practice Problems & Coding Challenges

Challenge - 5 Problems

❓ Predict Output

intermediate

What is the output of this retry example?

Consider the following Ruby code using retry. What will it print?

Ruby

count = 0
begin
  count += 1
  puts "Attempt #{count}"
  raise 'fail' if count < 3
rescue
  retry
end
puts 'Done'

A

Attempt 1
Attempt 2
Attempt 3
Done

B

Attempt 1
Done

C

Attempt 1
Attempt 2
Done

D

Attempt 1
Attempt 2
Attempt 3
Attempt 4
Done

💡 Hint

The retry keyword restarts the begin block after rescue.

The code increments count each time. It raises an error until count reaches 3. Each rescue triggers retry, so it prints 'Attempt' three times before finishing.

❓ Predict Output

intermediate

What happens if retry is used outside rescue?

What error does this Ruby code produce?

Ruby

retry

A LocalJumpError

B RuntimeError

C SyntaxError

D NoMethodError

💡 Hint

retry can only be used inside rescue blocks.

Using retry outside rescue causes a LocalJumpError because Ruby expects retry only in rescue context.

🔧 Debug

advanced

Why does this retry loop never end?

Look at this code. Why does it print 'Trying...' forever?

Ruby

attempts = 0
begin
  attempts = 0
  attempts += 1
  puts 'Trying...'
  raise 'error'
rescue
  retry if attempts < 5
end
puts 'Finished'

A Because the condition to stop retry is never met

B Because retry restarts the begin block without changing attempts

C Because attempts is reset to 0 on each retry

D Because retry is inside rescue and causes infinite recursion

💡 Hint

Check if attempts changes between retries.

Every time `retry` is executed, it restarts the `begin` block from the top. The `attempts = 0` inside the begin block resets the counter each time, so `attempts` becomes 1 after increment and is always < 5 when checked, causing infinite retries.

📝 Syntax

advanced

Which option causes a syntax error related to retry?

Which of these Ruby snippets will cause a syntax error?

A

begin
  raise 'fail'
rescue
  puts 'error'
  retry
end

B

begin
  raise 'fail'
rescue
  retry
end

C

begin
  raise 'fail'
rescue
  retry if true
end

D

begin
  retry
rescue
  puts 'error'
end

💡 Hint

retry must be inside rescue block, not before it.

Option D uses retry inside begin block before rescue, which is invalid syntax. retry must be inside rescue block.

🚀 Application

expert

How many times does this retry block execute?

Given this Ruby code, how many times will 'Processing...' be printed?

Ruby

count = 0
begin
  count += 1
  puts 'Processing...'
  raise 'error' if count < 4
rescue
  retry
end

A Infinite loop

B 4

C 5

D 3

💡 Hint

Does the retry condition ever stop?

The `raise` only happens if `count < 4`. It prints and raises for count=1,2,3 (retrying each time), then for count=4 prints but does not raise, skipping rescue and exiting the block. Thus, printed 4 times.