Loop method for infinite loops in Ruby - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to create an infinite loop using the loop method.

Ruby

loop do
  puts "Hello, world!"
  [1]
end

Drag options to blanks, or click blank then click option'

Abreak

Bexit

Credo

Dnext

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'break' will stop the loop immediately.

Using 'exit' will stop the entire program.

The next keyword skips to the next iteration, so the loop continues infinitely.

2fill in blank

medium

Complete the code to print numbers from 1 to 5 inside an infinite loop, then break the loop.

Ruby

i = 1
loop do
  puts i
  i += 1
  [1]
end

Drag options to blanks, or click blank then click option'

Aredo if i > 5

Bnext if i > 5

Cbreak if i > 5

Dexit if i > 5

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'next' will skip the rest of the iteration but not stop the loop.

Using 'exit' will stop the whole program, not just the loop.

The break if i > 5 stops the infinite loop after printing numbers 1 to 5.

3fill in blank

hard

Fix the error in the code to create an infinite loop that prints 'Looping'.

Ruby

loop [1]
  puts 'Looping'
end

Drag options to blanks, or click blank then click option'

Awhile true do

Bdo

Cuntil false do

Dfor

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'while true do' after 'loop' is incorrect syntax.

Using 'for' is not valid with 'loop'.

The correct syntax for an infinite loop using the loop method is loop do.

4fill in blank

hard

Fill both blanks to create an infinite loop that prints 'Tick' every second.

Ruby

loop [1]
  puts 'Tick'
  sleep [2]
end

Drag options to blanks, or click blank then click option'

Ado

Bwhile true do

C1

D0.5

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'while true do' after 'loop' is incorrect syntax.

Using 'sleep 0.5' will pause for half a second, not one second.

The loop do syntax creates an infinite loop, and sleep 1 pauses for one second each iteration.

5fill in blank

hard

Fill all three blanks to create an infinite loop that counts from 1 upwards and breaks after 10.

Ruby

count = [1]
loop [2]
  puts count
  count += [3]
  break if count > 10
end

Drag options to blanks, or click blank then click option'

A0

Bdo

C1

D10

Attempts:

3 left

💡 Hint

Common Mistakes

Starting count at 1 will print 1 to 11 instead of 1 to 10.

Using 'while true do' instead of 'do' after 'loop' is incorrect.

Start counting at 0, use loop do for the infinite loop, and increase count by 1 each time.

Practice

1. What does the Ruby code loop do; puts "Hello"; break; end do?

easy

A. Prints "Hello" once and stops the loop

B. Prints "Hello" infinitely without stopping

C. Causes a syntax error

D. Prints nothing

Solution

1. Step 1: Understand the loop structure

   The loop do ... end creates an infinite loop that repeats the code inside.

2. Step 2: Analyze the break statement

   The break immediately stops the loop after printing "Hello" once.

3. Final Answer:

   Prints "Hello" once and stops the loop -> Option A

4. Quick Check:

   loop with break stops after one iteration [OK]

Hint: Remember: break stops the infinite loop immediately [OK]

Common Mistakes:

• Thinking loop runs forever even with break
• Confusing loop with while
• Ignoring the break statement

2. Which of the following is the correct syntax to create an infinite loop using the loop method in Ruby?

easy

A. loop: do puts "Hi" end

B. loop { puts "Hi" do end }

C. loop puts "Hi" do end

D. loop { puts "Hi" }

Solution

1. Step 1: Review Ruby loop syntax

   The loop method can take a block with curly braces or do...end.

2. Step 2: Identify correct syntax

   loop { puts "Hi" } uses loop { puts "Hi" }, which is valid Ruby syntax for an infinite loop.

3. Final Answer:

   loop { puts "Hi" } -> Option D

4. Quick Check:

   loop with block braces is valid syntax [OK]

Hint: Use loop with { } or do...end for blocks [OK]

Common Mistakes:

• Placing do after loop without block
• Using colon incorrectly
• Missing block braces or do...end

3. What will be the output of the following Ruby code?

count = 0
loop do
  puts count
  count += 1
  break if count == 3
end

medium

A. 0 1 2 3

B. 0 1 2

C. 1 2 3

D. Infinite loop printing numbers

Solution

1. Step 1: Trace the loop iterations

   Initially, count = 0. The loop prints count, then increments it by 1.

2. Step 2: Check break condition

   Loop breaks when count == 3, so it stops after printing 0, 1, and 2.

3. Final Answer:

   0 1 2 -> Option B

4. Quick Check:

   Loop stops before printing 3 due to break condition [OK]

Hint: Break stops loop before count reaches 3 [OK]

Common Mistakes:

• Including 3 in output
• Forgetting to increment count
• Assuming infinite loop

4. Identify the error in the following Ruby code using loop do:

loop do
  puts "Start"
  break
  puts "End"
end

medium

A. The code after break will never execute

B. The break statement is unreachable

C. Syntax error due to missing end

D. Infinite loop without break

Solution

1. Step 1: Understand break behavior

   The break stops the loop immediately when reached.

2. Step 2: Analyze code after break

   The puts "End" after break will never run because break exits the loop first.

3. Final Answer:

   The code after break will never execute -> Option A

4. Quick Check:

   Code after break is skipped [OK]

Hint: Code after break inside loop is ignored [OK]

Common Mistakes:

• Thinking code after break runs
• Confusing break with next
• Assuming syntax error

5. How can you use the Ruby loop do method to repeatedly ask a user for input until they type "exit"?

hard

A. Use loop without break and rely on user to close program

B. Use while loop with condition input != "exit"

C. Use loop with gets and break if input equals "exit"

D. Use for loop iterating over input strings

Solution

1. Step 1: Use loop to repeat input request

   The loop do method runs code repeatedly until broken.

2. Step 2: Use break with condition on user input

   Inside the loop, get user input with gets.chomp and break if input is "exit".

3. Final Answer:

   Use loop with gets and break if input equals "exit" -> Option C

4. Quick Check:

   loop + break on condition = controlled infinite loop [OK]

Hint: Break loop when input matches exit string [OK]

Common Mistakes:

• Not using break to stop loop
• Using wrong loop type
• Forgetting to remove newline from input