Break statement in Javascript - Practice Problems & Coding Challenges

Challenge - 5 Problems

❓ Predict Output

intermediate

What is the output of this code using break in a loop?

Look at the code below. What will it print to the console?

Javascript

let result = '';
for (let i = 0; i < 5; i++) {
  if (i === 3) {
    break;
  }
  result += i;
}
console.log(result);

A "012"

B "01234"

C "123"

D "0123"

💡 Hint

Remember, break stops the loop immediately when the condition is met.

The loop adds numbers 0, 1, and 2 to the string. When i becomes 3, the break stops the loop before adding 3.

❓ Predict Output

intermediate

What happens when break is inside a nested loop?

What will this code print to the console?

Javascript

let output = '';
for (let i = 0; i < 3; i++) {
  for (let j = 0; j < 3; j++) {
    if (j === 1) {
      break;
    }
    output += `${i}${j} `;
  }
}
console.log(output.trim());

A "00 01 02 10 11 12 20 21 22"

B "00 01 10 11 20 21"

C "00 10 20"

D "00 10 20 21"

💡 Hint

Break only stops the inner loop, not the outer one.

The inner loop breaks when j equals 1, so only j=0 is added for each i. The outer loop continues for i=0,1,2.

❓ Predict Output

advanced

What is the output when break is used inside a switch statement?

Check the code below. What will it print?

Javascript

const value = 2;
switch (value) {
  case 1:
    console.log('One');
    break;
  case 2:
    console.log('Two');
    break;
  case 3:
    console.log('Three');
    break;
  default:
    console.log('Default');
}

A "Two\nThree"

B "Two"

C "One\nTwo"

D "One\nTwo\nThree"

💡 Hint

Remember that break stops the switch from continuing to the next cases.

Since value is 2, it matches case 2 and prints 'Two'. The break stops further cases from running.

❓ Predict Output

advanced

What error does this code raise?

What error will this code cause when run?

Javascript

while (true) {
  if (false) {
    break;
  }
  console.log('Looping');
  break;
  break;
}

A SyntaxError

B Infinite loop

C TypeError

D No error, prints 'Looping' once

💡 Hint

Multiple break statements in a row are allowed but some may be unreachable.

The code prints 'Looping' once and then breaks out of the loop. No syntax or runtime error occurs.

🧠 Conceptual

expert

Which option correctly explains break behavior in nested loops?

In JavaScript, what does the break statement do inside nested loops?

A Break exits only the innermost loop where it is called.

B Break exits all loops regardless of nesting level.

C Break exits the outermost loop only.

D Break pauses the loop but continues after a delay.

💡 Hint

Think about which loop the break is inside.

Break stops the closest loop it is inside. Outer loops continue unless they also have a break.

Practice

1. What does the break statement do inside a loop in JavaScript?

easy

A. Pauses the loop for a moment

B. Stops the loop immediately and exits it

C. Restarts the loop from the beginning

D. Skips the current iteration and continues with the next

Solution

1. Step 1: Understand the purpose of break

   The break statement is used to stop a loop or switch case immediately.

2. Step 2: Compare with other loop controls

   Unlike continue which skips to the next iteration, break exits the loop fully.

3. Final Answer:

   Stops the loop immediately and exits it -> Option B

4. Quick Check:

   break stops loop = D [OK]

Hint: Break exits loop immediately, unlike continue which skips iteration [OK]

Common Mistakes:

• Confusing break with continue
• Thinking break pauses the loop
• Assuming break restarts the loop

2. Which of the following is the correct syntax to use break inside a for loop?

easy

A. for(let i=0; i<5; i++) { if(i===3) break; }

B. for(let i=0; i<5; i++) { break if(i===3); }

C. for(let i=0; i<5; i++) { if break(i===3); }

D. for(let i=0; i<5; i++) { if(i===3) continue break; }

Solution

1. Step 1: Check the correct placement of break

   The break statement must be inside a block and triggered by a condition like if(i===3).

2. Step 2: Validate syntax correctness

   for(let i=0; i<5; i++) { if(i===3) break; } uses correct JavaScript syntax: if(condition) break;. Other options misuse break syntax.

3. Final Answer:

   for(let i=0; i<5; i++) { if(i===3) break; } -> Option A

4. Quick Check:

   Correct break syntax = B [OK]

Hint: Use break inside if block: if(condition) break; [OK]

Common Mistakes:

• Placing break before if
• Using break as a function
• Combining continue and break incorrectly

3. What will be the output of this code?

let sum = 0;
for(let i = 1; i <= 5; i++) {
  if(i === 3) break;
  sum += i;
}
console.log(sum);

medium

A. 3

B. 6

C. 10

D. 15

Solution

1. Step 1: Trace the loop iterations

   The loop runs from i=1 to i=5, but breaks when i equals 3, so it runs for i=1 and i=2 only.

2. Step 2: Calculate the sum before break

   sum = 0 + 1 + 2 = 3; loop breaks before adding 3.

3. Final Answer:

   3 -> Option A

4. Quick Check:

   Sum before break at i=3 = 3 [OK]

Hint: Add only before break triggers; break stops loop early [OK]

Common Mistakes:

• Adding value after break condition
• Assuming loop runs fully
• Confusing break with continue

4. Find the error in this code snippet:

for(let i=0; i<5; i++) {
  if(i === 2)
    break
  console.log(i);
}

medium

A. Missing semicolon after break causes syntax error

B. break cannot be used inside for loops

C. No error, code runs correctly

D. console.log should be before break

Solution

1. Step 1: Check syntax of break statement

   In JavaScript, semicolon after break is optional if line ends there, so no syntax error.

2. Step 2: Verify loop and break usage

   break is valid inside for loops and console.log after break is fine; code stops when i=2.

3. Final Answer:

   No error, code runs correctly -> Option C

4. Quick Check:

   break syntax valid without semicolon = C [OK]

Hint: Semicolon after break is optional if line ends there [OK]

Common Mistakes:

• Thinking semicolon is mandatory after break
• Believing break can't be in loops
• Assuming console.log must be before break

5. You want to find the first number divisible by 7 in an array and stop checking after finding it. Which code correctly uses break to do this?

const numbers = [10, 13, 21, 28, 35];
let result = null;
for(let num of numbers) {
  if( /* condition here */ ) {
    result = num;
    break;
  }
}
console.log(result);

hard

A. if(num === 7)

B. if(num / 7 === 0)

C. if(num % 7)

D. if(num % 7 === 0)

Solution

1. Step 1: Identify condition for divisibility by 7

   Use modulo operator: num % 7 === 0 checks if remainder is zero, meaning divisible.

2. Step 2: Confirm break usage stops loop after first match

   When condition is true, assign result and break to stop checking further.

3. Final Answer:

   if(num % 7 === 0) -> Option D

4. Quick Check:

   Modulo zero means divisible = A [OK]

Hint: Use modulo (%) to check divisibility, then break [OK]

Common Mistakes:

• Using division instead of modulo
• Checking if num equals 7 only
• Using if(num % 7) which is truthy for non-zero