Break, next, and redo behavior in Ruby - Practice Problems & Coding Challenges

Challenge - 5 Problems

❓ Predict Output

intermediate

What is the output of this Ruby code using break?

Consider the following Ruby code snippet. What will it print when run?

Ruby

arr = [1, 2, 3, 4, 5]
result = []
arr.each do |x|
  break if x > 3
  result << x
end
puts result.inspect

A [1, 2, 3]

B [1, 2]

C [1, 2, 3, 4]

D [1, 2, 3, 4, 5]

💡 Hint

Remember that break exits the loop immediately when the condition is true.

The loop adds elements to result until it encounters a value greater than 3. When x is 4, break stops the loop, so only 1, 2, and 3 are added.

❓ Predict Output

intermediate

What does next do in this Ruby loop?

Look at this Ruby code. What will be printed?

Ruby

result = []
(1..5).each do |i|
  next if i.even?
  result << i
end
puts result.inspect

A []

B [2, 4]

C [1, 2, 3, 4, 5]

D [1, 3, 5]

💡 Hint

next skips the current iteration and moves to the next one.

The loop skips even numbers using next, so only odd numbers 1, 3, and 5 are added to result.

❓ Predict Output

advanced

What is the output when using redo inside a loop?

Analyze this Ruby code. What will it print?

Ruby

count = 0
(1..3).each do |i|
  puts i
  count += 1
  redo if count < 3
  count = 0
end

A

1
1
1
1
1
... (infinite loop)

B

1
2
3

C

1
1
1
2
2
2
3
3
3

D

1
2
2
3
3
3

💡 Hint

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

For each i, the loop prints i and increments count. redo repeats the iteration until count reaches 3, then resets count and moves on.

🔧 Debug

advanced

Why does this Ruby code cause an infinite loop?

This Ruby code uses redo inside a loop. Why does it never end?

Ruby

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

A Because i is never incremented before redo repeats the iteration, so i stays 0 forever.

B Because redo skips the i += 1 line, so i increments too fast.

C Because the condition i < 3 is always false.

D Because puts i causes an error stopping the loop.

💡 Hint

Think about what redo does to the flow of the loop and when i changes.

redo restarts the current iteration without running the code after it. Since i += 1 is after redo, i never changes, causing an infinite loop.

🧠 Conceptual

expert

How do break, next, and redo differ in Ruby loops?

Which statement correctly describes the behavior of break, next, and redo in Ruby loops?

A break exits the entire loop immediately; next skips to the next iteration; redo repeats the current iteration without re-evaluating the loop condition.

B break skips the current iteration; next exits the loop; redo moves to the next iteration.

C break repeats the current iteration; next exits the loop; redo skips the current iteration.

D break and next both exit the loop; redo skips the rest of the loop body.

💡 Hint

Think about what each keyword does to the flow of the loop.

break stops the loop completely, next skips the rest of the current iteration and moves on, and redo restarts the current iteration without checking the loop condition again.