Retry for reattempting in Ruby - Cheat Sheet & Quick Revision

Recall & Review

beginner

What does the retry keyword do in Ruby?

The retry keyword restarts the execution of the begin block from the start, allowing you to try the code again after an exception.

beginner

Where can you use retry in Ruby code?

You can use retry inside a rescue block to reattempt the code inside the begin block after an error occurs.

intermediate

What happens if retry is used outside a rescue block?

Using retry outside a rescue block causes a syntax error because Ruby expects it only to be used for reattempting after an exception.

intermediate

How can you limit the number of retries in Ruby?

You can use a counter variable to track how many times you retried and use retry only if the count is below a limit, preventing infinite loops.

beginner

Example: What will this code print?

attempt = 0
begin
  attempt += 1
  puts "Try #{attempt}"
  raise "Fail" if attempt < 3
rescue
  retry
end
puts "Success on try #{attempt}"

The code prints:<br>Try 1<br>Try 2<br>Try 3<br>Success on try 3<br>It retries twice after failures and succeeds on the third try.

What does retry do inside a rescue block?

A Restarts the <code>begin</code> block from the start

B Skips the rest of the <code>rescue</code> block

C Exits the program immediately

D Ignores the exception and continues

retry restarts the begin block, allowing the code to try again.

What happens if retry is used outside a rescue block?

A It works normally

B It retries the last method call

C It causes a syntax error

D It raises an exception

retry must be inside a rescue block; otherwise, Ruby raises a syntax error.

How can you prevent infinite retries when using retry?

A You cannot prevent infinite retries

B Use <code>break</code> inside <code>rescue</code>

C Use <code>next</code> instead of <code>retry</code>

D Use a counter to limit retries

A counter variable helps limit how many times retry is called.

Which keyword is paired with retry to handle errors?

A begin

B rescue

C ensure

D else

retry is used inside rescue blocks to reattempt the begin block.

What will happen if retry is called without any exception being raised?

A It causes a runtime error

B It does nothing

C The code restarts anyway

D It skips the <code>rescue</code> block

retry is only valid after an exception; calling it otherwise causes an error.

Explain how the retry keyword works in Ruby and when you would use it.

Think about what happens after an error and how you can try again.

Describe a safe way to use retry to avoid infinite loops.

Consider counting how many times you tried.