Break statement with levels in PHP - Practice Problems & Coding Challenges

Challenge - 5 Problems

❓ Predict Output

intermediate

Output of nested loops with break 2

What is the output of this PHP code using break 2 inside nested loops?

PHP

<?php
for ($i = 1; $i <= 3; $i++) {
    for ($j = 1; $j <= 3; $j++) {
        if ($j == 2) {
            break 2;
        }
        echo "$i$j ";
    }
}
?>

A 11

B 11 12 13 21 22 23 31 32 33

C 11 12

D 12

💡 Hint

Remember that break 2 exits two levels of loops immediately.

The break 2 statement exits both the inner and outer loops as soon as $j == 2. So only the first iteration 11 is printed before breaking out.

❓ Predict Output

intermediate

Effect of break 1 in nested loops

What will be the output of this PHP code using break 1 inside nested loops?

PHP

<?php
for ($i = 1; $i <= 2; $i++) {
    for ($j = 1; $j <= 3; $j++) {
        if ($j == 2) {
            break 1;
        }
        echo "$i$j ";
    }
}
?>

A 11 12 21 22

B 11 21

C 11 12 13 21 22 23

D 11 21 22

💡 Hint

break 1 only exits the innermost loop.

The break 1 exits only the inner loop when $j == 2. So for each outer loop iteration, only $j == 1 prints. Output is '11 21 '.

🔧 Debug

advanced

Identify error with break level

What error will this PHP code produce when using break 3 inside two nested loops?

PHP

<?php
for ($i = 0; $i < 2; $i++) {
    for ($j = 0; $j < 2; $j++) {
        if ($j == 1) {
            break 3;
        }
        echo "$i$j ";
    }
}
?>

A Fatal error: Cannot break 3 levels

B No output, loops run fully

C Output: 0001

D Syntax error: unexpected break

💡 Hint

Check how many nested loops exist and the break level used.

The code tries to break 3 levels but only 2 loops exist. PHP throws a fatal error: 'Cannot break 3 levels'.

❓ Predict Output

advanced

Output with break in switch inside loops

What is the output of this PHP code with break 2 inside a switch within nested loops?

PHP

<?php
for ($i = 1; $i <= 3; $i++) {
    for ($j = 1; $j <= 3; $j++) {
        switch ($j) {
            case 2:
                break 2;
            default:
                echo "$i$j ";
        }
    }
}
?>

A 11 13 21 23 31 33

B 11 12 13 21 22 23 31 32 33

C 11

D 12

💡 Hint

Remember break 2 exits two control structures, here loops and switch.

The break 2 inside the switch exits both the switch and the outer for loop. So only '11 ' prints before exiting all loops.

🧠 Conceptual

expert

Understanding break levels in complex nested structures

Consider this PHP code with three nested loops and a break 2 inside the innermost loop. After the break executes, which loops continue running?

PHP

<?php
for ($a = 1; $a <= 2; $a++) {
    for ($b = 1; $b <= 2; $b++) {
        for ($c = 1; $c <= 2; $c++) {
            if ($c == 2) {
                break 2;
            }
            echo "$a$b$c ";
        }
    }
}
?>

A Only the outermost loop continues; the two inner loops break

B Only the innermost loop breaks; middle and outer loops continue

C All three loops break and stop running

D The innermost and middle loops break; outer loop continues

💡 Hint

Break level counts how many nested loops to exit starting from innermost.

break 2 exits the innermost and the middle loops. The outermost loop continues its next iteration.

Practice

1.

What does the break statement do in PHP loops?

easy

A. It skips the current iteration and continues the loop.

B. It pauses the loop until a condition is met.

C. It restarts the loop from the beginning.

D. It stops the current loop immediately.

Solution

1. Step 1: Understand the purpose of break

   The break statement is used to exit a loop early when a condition is met.

2. Step 2: Compare options

   The description "It stops the current loop immediately." correctly describes break. "It skips the current iteration..." describes continue. Restarting or pausing are incorrect.

3. Final Answer:

   It stops the current loop immediately. -> Option D

4. Quick Check:

   break stops loop [OK]

Hint: Break stops loops immediately, no more iterations [OK]

Common Mistakes:

• Confusing break with continue
• Thinking break pauses instead of stops
• Assuming break restarts the loop

2.

Which of the following is the correct syntax to break out of 2 nested loops in PHP?

for (...) {
    for (...) {
        // break here
    }
}

easy

A. break;

B. break(2);

C. break 2;

D. break 1;

Solution

1. Step 1: Recall break syntax with levels

   To exit multiple nested loops, PHP uses break n; where n is the number of loops to break out of.

2. Step 2: Identify correct syntax

   break 2; correctly breaks out of 2 loops. break(2); is invalid syntax. A plain break; or break 1; breaks only one loop.

3. Final Answer:

   break 2; -> Option C

4. Quick Check:

   break 2; exits 2 loops [OK]

Hint: Use break n; to exit n nested loops in PHP [OK]

Common Mistakes:

• Using break(2) which is invalid syntax
• Forgetting to specify number for multiple loops
• Using break 1; when 2 loops need exit

3.

What is the output of this PHP code?

$count = 0;
for ($i = 0; $i < 3; $i++) {
    for ($j = 0; $j < 3; $j++) {
        $count++;
        if ($i + $j == 2) {
            break 2;
        }
    }
}
echo $count;

medium

A. 5

B. 3

C. 4

D. 6

Solution

1. Step 1: Trace nested loops and break condition

   Loops run with i and j from 0 to 2. The break triggers when i + j == 2, breaking out of both loops immediately. count++ occurs before the check.

2. Step 2: Simulate iterations

   - i=0,j=0: count=1 (sum=0 !=2)
   - i=0,j=1: count=2 (sum=1 !=2)
   - i=0,j=2: count=3 (sum=2 ==2), break 2; loops stop
   Total count = 3.

3. Final Answer:

   3 -> Option B

4. Quick Check:

   3 increments before break 2 exits both loops [OK]

Hint: Count increments before break; break n exits n loops [OK]

Common Mistakes:

• Counting increments after break condition
• Ignoring break level effect
• Assuming break only exits inner loop

4.

Find the error in this PHP code snippet:

for ($i = 0; $i < 3; $i++) {
    for ($j = 0; $j < 3; $j++) {
        if ($i == $j) {
            break 3;
        }
        echo "$i,$j\n";
    }
}

medium

A. break 3; is invalid because only 2 loops exist.

B. break 3; should be break 2; to exit both loops.

C. break 3; causes infinite loop.

D. No error, code runs fine.

Solution

1. Step 1: Count nested loops

   There are 2 nested loops: outer and inner.

2. Step 2: Check break level usage

   Using break 3; tries to break out of 3 loops, but only 2 exist, causing a fatal error.

3. Final Answer:

   break 3; is invalid because only 2 loops exist. -> Option A

4. Quick Check:

   break n must be ≤ nested loops count [OK]

Hint: Break level cannot exceed nested loops count [OK]

Common Mistakes:

• Using break level higher than loops
• Assuming break 3 exits 2 loops
• Ignoring PHP fatal error on invalid break level

5.

You want to stop processing nested loops early when a condition is met, but only exit the inner loop sometimes and both loops other times. Which code snippet correctly uses break with levels?

for ($i = 0; $i < 5; $i++) {
    for ($j = 0; $j < 5; $j++) {
        if ($i == 2 && $j == 3) {
            break 2; // exit both loops
        } elseif ($j == 4) {
            break; // exit inner loop only
        }
        echo "$i,$j\n";
    }
}

hard

A. Correct use of break with levels to control loop exit.

B. break 2; should be break 1; to exit both loops.

C. break; cannot be used inside nested loops.

D. break 2; exits only the inner loop.

Solution

1. Step 1: Understand break with levels usage

   break 2; exits two loops, break; exits only the current loop.

2. Step 2: Analyze code logic

   When $i==2 && $j==3, both loops exit with break 2;. When $j==4, only inner loop exits with break;. This matches the requirement.

3. Final Answer:

   Correct use of break with levels to control loop exit. -> Option A

4. Quick Check:

   break n exits n loops, break exits current loop [OK]

Hint: Use break n; for multiple loops, break; for single loop exit [OK]

Common Mistakes:

• Confusing break 2; with break 1;
• Thinking break; exits all loops
• Misusing break levels causing logic errors