Break, next, and redo behavior in Ruby - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to exit the loop when the number is 5.

Ruby

numbers = [1, 2, 3, 4, 5, 6]
numbers.each do |num|
  if num == 5
    [1]
  end
  puts num
end

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

Anext

Bbreak

Credo

Dreturn

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'next' instead of 'break' which skips to the next iteration.

Using 'redo' which repeats the current iteration endlessly.

The break keyword exits the loop immediately when the condition is met.

2fill in blank

medium

Complete the code to skip printing the number 3 but continue the loop.

Ruby

numbers = [1, 2, 3, 4, 5]
numbers.each do |num|
  if num == 3
    [1]
  end
  puts num
end

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

Anext

Bredo

Cbreak

Dexit

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'break' which stops the entire loop.

Using 'redo' which repeats the current iteration endlessly.

The next keyword skips the current iteration and continues with the next one.

3fill in blank

hard

Fix the error in the code to repeat the current iteration when the number is even.

Ruby

numbers = [1, 2, 3]
numbers.each do |num|
  if num.even?
    [1]
  end
  puts num
end

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

Abreak

Bretry

Cnext

Dredo

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'next' which skips to the next iteration.

Using 'retry' which is not valid inside this loop context.

The redo keyword repeats the current iteration without moving to the next element.

4fill in blank

hard

Fill both blanks to skip printing 2 and stop the loop at 4.

Ruby

numbers = [1, 2, 3, 4, 5]
numbers.each do |num|
  if num == 2
    [1]
  elsif num == 4
    [2]
  end
  puts num
end

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

Anext

Bbreak

Credo

Dreturn

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'break' to skip 2 which stops the whole loop.

Using 'redo' which repeats the iteration endlessly.

Use next to skip printing 2 and break to stop the loop at 4.

5fill in blank

hard

Fill all three blanks to repeat the iteration for odd numbers, skip 4, and stop at 5.

Ruby

numbers = [1, 2, 3, 4, 5]
numbers.each do |num|
  if num.odd?
    [1]
  elsif num == 4
    [2]
  elsif num == 5
    [3]
  end
  puts num
end

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

Aredo

Bnext

Cbreak

Dreturn

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'next' instead of 'redo' for repeating.

Using 'break' too early stopping the loop before intended.

Use redo to repeat the iteration for odd numbers, next to skip 4, and break to stop at 5.

Practice

1. What does the break keyword do inside a Ruby loop?

easy

A. Stops the loop completely and exits it

B. Skips the current iteration and moves to the next

C. Repeats the current iteration without moving forward

D. Pauses the loop until a condition is met

Solution

1. Step 1: Understand the role of break

   The break keyword immediately stops the loop and exits it, no further iterations happen.

2. Step 2: Compare with other keywords

   next skips to the next iteration, redo repeats the current one, but break stops all looping.

3. Final Answer:

   Stops the loop completely and exits it -> Option A

4. Quick Check:

   break = stop loop [OK]

Hint: Break means stop the loop right away [OK]

Common Mistakes:

• Confusing break with next
• Thinking break repeats iteration
• Assuming break pauses instead of stops

2. Which of the following is the correct syntax to skip the current iteration in a Ruby loop?

easy

A. break

B. next

C. redo

D. skip

Solution

1. Step 1: Identify the keyword for skipping iteration

   The keyword next is used in Ruby to skip the rest of the current loop iteration and move to the next one.

2. Step 2: Check other options

   break stops the loop, redo repeats the current iteration, and skip is not a Ruby keyword.

3. Final Answer:

   next -> Option B

4. Quick Check:

   Skip iteration = next [OK]

Hint: Use next to jump to next loop step [OK]

Common Mistakes:

• Using break instead of next
• Trying to use skip keyword (not valid)
• Confusing redo with next

3. What is the output of this Ruby code?

i = 0
while i < 3
  i += 1
  if i == 2
    redo
  end
  puts i
end

medium

A. 1 2 2 2 ... (infinite loop)

B. 1 3

C. 1 2 3

D. 1 3 3

Solution

1. Step 1: Trace the loop and redo behavior

   When i == 2, redo repeats the current iteration without incrementing i again, causing the loop to print 2 repeatedly.

2. Step 2: Understand infinite repetition

   Since i is not changed inside the redo loop, it never moves past 2, causing an infinite loop printing 2 repeatedly.

3. Final Answer:

   1 2 2 2 ... (infinite loop) -> Option A

4. Quick Check:

   redo repeats current step causing infinite loop [OK]

Hint: Redo repeats current step, watch for infinite loops [OK]

Common Mistakes:

• Assuming i increments inside redo
• Thinking redo skips iteration
• Ignoring infinite loop possibility

4. Find the error in this Ruby code snippet:

for i in 1..3
  if i == 2
    next
  elsif i == 3
    redo
  end
  puts i
end

medium

A. puts should be before if statement

B. next cannot be used inside for loops

C. Syntax error: missing end for if

D. Using redo inside for loop causes infinite loop

Solution

1. Step 1: Analyze the use of redo in the loop

   The redo inside the elsif i == 3 causes the loop to repeat the same iteration infinitely because i does not change.

2. Step 2: Check other options for errors

   next works fine in for loops, the if statement is properly closed, and puts can be after if.

3. Final Answer:

   Using redo inside for loop causes infinite loop -> Option D

4. Quick Check:

   Redo repeats current step causing infinite loop [OK]

Hint: Redo without changing loop variable causes infinite loop [OK]

Common Mistakes:

• Thinking next is invalid in for loops
• Missing that redo repeats without increment
• Assuming syntax error due to indentation

5. You want to print numbers 1 to 5 but skip 3 and repeat printing 4 twice using next and redo. Which code achieves this correctly?

i = 0
while i < 5
  i += 1
  if i == 3
    # skip 3
  elsif i == 4
    # print 4 twice
  end
  puts i
end

hard

A. if i == 3
next
elsif i == 4
puts i
redo
next
end

B. if i == 3
next
elsif i == 4
redo
end

C. if i == 3
next
elsif i == 4
puts i
redo
end

D. if i == 3
redo
elsif i == 4
next
end

Solution

1. Step 1: Skip number 3 using next

   Using next when i == 3 skips printing 3 and moves to next iteration.

2. Step 2: Repeat printing 4 twice using redo

   When i == 4, print it once, then use redo to repeat the iteration and print 4 again.

3. Step 3: Verify code correctness

   if i == 3 next elsif i == 4 puts i redo end prints 4, then calls redo to repeat printing 4, and skips 3 correctly. Other options misuse next or redo causing errors or infinite loops.

4. Final Answer:

   if i == 3 next elsif i == 4 puts i redo end -> Option C

5. Quick Check:

   next skips, redo repeats current step [OK]

Hint: Use next to skip, redo after puts to repeat [OK]

Common Mistakes:

• Calling redo before puts causing infinite loop
• Using next after redo incorrectly
• Not skipping 3 properly