Repeat loop with break in R Programming - Step-by-Step Execution

Concept Flow - Repeat loop with break

Start repeat loop

↓

Execute loop body

↓

Check break condition

↓

Exit loop

The repeat loop runs its body repeatedly until a break condition is met, then it exits.

Execution Sample

R Programming

i <- 1
repeat {
  print(i)
  if (i == 3) break
  i <- i + 1
}

This code prints numbers from 1 to 3 using a repeat loop and breaks when i equals 3.

Execution Table

Step	i value	Condition (i == 3)?	Action	Output
1	1	No	Print 1; i <- 2	1
2	2	No	Print 2; i <- 3	2
3	3	Yes	Print 3; break loop	3
4	-	-	Loop exits	-

💡 At step 3, condition i == 3 is True, so break exits the loop.

Variable Tracker

Variable	Start	After 1	After 2	After 3	Final
i	1	2	3	3	3

Key Moments - 2 Insights

Why does the loop stop after printing 3?

Because at step 3 in the execution_table, the condition i == 3 is True, triggering the break statement which exits the loop immediately.

What happens if the break condition is never met?

The repeat loop would run forever because repeat loops only stop when break is called, as shown by the loop continuing when condition is No in steps 1 and 2.

Visual Quiz - 3 Questions

Look at the execution_table, what is the value of i at step 2?

A 2

B 1

C 3

D 4

💡 Hint

Check the 'i value' column at step 2 in the execution_table.

At which step does the loop exit?

A Step 2

B Step 4

C Step 3

D Step 1

💡 Hint

Look at the 'Action' column where break is called in the execution_table.

If we change the break condition to i == 5, what will happen to the output?

A It will print 1 to 3 and stop

B It will print 1 to 5 and then stop

C It will print 1 to 4 and then stop

D It will run forever without stopping

💡 Hint

i increments by 1 each loop after print if condition false; it will print 1-5 then break when i==5.

Concept Snapshot

repeat {
  # code
  if (condition) break
}

- repeat runs forever until break
- break exits loop immediately
- useful for loops with complex exit conditions

Full Transcript

This example shows how a repeat loop in R runs repeatedly until a break condition is met. We start with i = 1. Each loop prints i, then checks if i equals 3. If yes, break stops the loop. Otherwise, i increases by 1 and the loop repeats. The execution table tracks each step, showing i values, condition checks, actions, and output. The variable tracker shows how i changes after each iteration. Key moments clarify why the loop stops at 3 and what happens if break is never reached. The quiz tests understanding of i values, loop exit step, and effects of changing the break condition.