Break, next, and redo behavior in Ruby - Step-by-Step Execution

Concept Flow - Break, next, and redo behavior

Start Loop

↓

Check Condition

Yes↓

Inside Loop Body

↓

next?

Yes→Skip to Next Iteration

↓

redo?

Yes→Repeat Current Iteration

↓

break?

Yes→Exit Loop

↓

Continue Loop

↓

End Loop

The loop starts and checks the condition. Inside the loop, 'next' skips to the next iteration, 'redo' repeats the current iteration, and 'break' exits the loop immediately.

Execution Sample

Ruby

i = 0
loop do
  i += 1
  next if i == 2
  puts i
  break if i == 4
  redo if i == 3
end

This Ruby loop increments i, skips printing when i is 2, repeats the iteration when i is 3 (incrementing i to 4 on redo), and stops when i reaches 4. Output: 1 3 4

Execution Table

Step	i value	Condition	Action	Output
1	0 -> 1	i == 2? No	print 1, no break, no redo	1
2	1 -> 2	i == 2? Yes	next: skip print/break/redo
3	2 -> 3	i == 2? No	print 3, no break, redo triggers	3
4 (redo)	3 -> 4	i == 2? No	print 4, break triggers	4
5			exit loop

💡 Loop exits because i == 4 triggers break

Variable Tracker

Variable	Start	After Step 1	After Step 2	After Step 3	After Step 4	Final
i	0	1	2	3	4	4

Key Moments - 3 Insights

Why does i increase from 3 to 4 during the redo?

'redo' restarts the entire loop body from the top without re-checking the condition, so the 'i += 1' executes again, incrementing i to 4 (step 4).

Why is nothing printed when i equals 2?

The 'next' statement skips the rest of the loop body for that iteration, so the print statement is not executed (step 2).

What causes the loop to stop?

When i reaches 4 during the redo (step 4), the 'break' statement runs, immediately exiting the loop.

Visual Quiz - 3 Questions

Look at the execution table, what is the i value change at step 4?

A 2 -> 3

B 1 -> 2

C 3 -> 4

D 0 -> 1

💡 Hint

Check the 'i value' column for step 4 in the execution_table.

At which step does the loop skip printing the value of i?

A Step 1

B Step 2

C Step 3

D Step 4

💡 Hint

Look for the 'next' action in the Action column of the execution_table.

If the 'redo' line was removed, what would be printed after 3?

A 4

B 2

C Nothing, breaks

D Infinite 3

💡 Hint

Without 'redo', after printing 3 the loop continues to next iteration: i=4, print 4, break.

Concept Snapshot

Ruby loop control keywords:
- break: exits the loop immediately
- next: skips to the next iteration
- redo: repeats the current iteration without re-evaluating condition (re-executes body from start)
Use these inside loops to control flow precisely.

Full Transcript

This example shows a Ruby loop where i starts at 0. It prints 1, skips 2 with 'next', prints 3 then 'redo' which re-executes the body (i to 4, prints 4, breaks). The execution table traces each step accurately, showing how 'redo' increments i. Variable tracker shows i changes. Key moments explain redo increments because body restarts at 'i += 1'. Quiz tests step values and behaviors. Helps understand 'break', 'next', 'redo' in Ruby loops.