Does continue work in for...of loops?

Yes! continue works in all loop types: for, while, do...while, for...of, and for...in. It always skips to the next iteration.

Can I use break inside forEach?

No. break and continue don't work inside forEach (it's a function call, not a loop). Use for...of if you need break/continue, or use .some()/.every() for early exit with array methods.

Is it bad practice to use break?

Not at all. break makes intent clear: 'I found what I need, stop looking.' It's more efficient than continuing to loop unnecessarily. What IS bad practice is overusing labels or deeply nested break conditions.

What happens with continue in a while loop?

In a while loop, continue jumps back to the condition check. Be careful — if you put the counter update AFTER continue, it'll be skipped, potentially causing an infinite loop! Place updates before continue or use a for loop.

Can I break out of a switch inside a loop?

break in a switch exits the switch, not the loop. To break the loop from inside a switch, use a label on the loop: 'loop: for(...) { switch(...) { case x: break loop; } }'

JavaScript Loop Control

Control loop execution with break, continue, and labels.

Module 2 · Control Flow

Programs make decisions and repeat work. Conditionals choose paths, loops repeat actions, and nested structures combine both. Mastering control flow turns a script that runs once into software that reacts to data and user input.

Learn Loop Control in JavaScript — covering break, continue, Labels, Common Patterns with interactive visual examples and step-by-step explanations.

About this module

Control flow is how programs decide what to do next. If a user is logged in, show the dashboard; otherwise, redirect to login. If a cart total exceeds a threshold, apply a discount. These everyday behaviors all depend on conditionals and loops.

This module walks through if/else, switch, for and while loops, and how to combine them without losing readability. Visual step-throughs help you see exactly which branch runs and how loop counters change on each iteration.

Why this matters

Understanding loop control is essential for every JavaScript developer. It shows up in frontend UI code, backend APIs, and framework internals — and getting it wrong leads to bugs that are hard to trace. This chapter builds intuition with visuals so the behavior sticks.

Key topics covered

break
continue
Labels
Common Patterns

Where you'll use it

Building interactive web applications with loop control
Processing and transforming data in frontend and backend code
Writing cleaner, more maintainable JavaScript modules
Debugging and reviewing code during development

break

Exit a loop immediately. Stop iterating.

The break statement terminates the current loop entirely. Execution jumps to the first statement after the loop.

for (let i = 0; i < 10; i++) {
  if (i === 5) break;  // ← exit here
  console.log(i);
}
// Output: 0, 1, 2, 3, 4
// (5 through 9 never execute)

break at i ===5

Output: 0, 1, 2, 3, 4

// Search and stop when found:
const users = ["Alice", "Bob", "Charlie", "Dave"];
let found = null;

for (const user of users) {
  if (user === "Charlie") {
    found = user;
    break; // No need to check the rest
  }
}
console.log(found); // "Charlie"

Use break to stop searching once you've found what you need. More efficient than checking all items.

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continue

Skip the current iteration. Move to the next one.

The continue statement skips the rest of the current iteration and jumps to the next one (including the update expression in for loops).

for (let i = 0; i < 8; i++) {
  if (i === 3) continue; // ← skip this one
  console.log(i);
}
// Output: 0, 1, 2, 4, 5, 6, 7
// (3 is skipped, but loop continues)

skip when i ===3

Output: 0, 1, 2, 4, 5, 6, 7

🛑

break

Exit loop completely

No more iterations

⏭️

continue

Skip this iteration

Loop keeps going

// Skip even numbers:
for (let i = 0; i < 10; i++) {
  if (i % 2 === 0) continue;
  console.log(i); // 1, 3, 5, 7, 9
}

// Skip empty values:
const items = ["apple", "", "banana", null, "cherry"];
for (const item of items) {
  if (!item) continue; // skip falsy values
  console.log(item);   // apple, banana, cherry
}

Labels

Break or continue outer loops from inside nested loops.

Normally, break and continue only affect the innermost loop. Labels let you target an outer loop.

// Label syntax:
labelName: for (...) {
  for (...) {
    break labelName;    // exits the OUTER loop
    continue labelName; // skips to next OUTER iteration
  }
}

// Find first pair that sums to 10:
outer: for (let i = 0; i < 5; i++) {
  for (let j = 0; j < 5; j++) {
    if (i + j === 10) {
      console.log(i, j);
      break outer; // exit BOTH loops
    }
  }
}

Without the label, break would only exit the inner loop. The outer loop would keep running.

💡 break outer exits BOTH loops at once

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outer:for (let i = 0; i < 3; i++)

for (let j = 0; j < 3; j++)

break→ exits inner only

break outer→ exits both loops

⚠️ Labels are rarely needed. Most cases can be solved by extracting logic into a function and using return instead. Use labels sparingly.

Common Patterns

Real-world uses of break and continue.

1. Early Exit — Find First Match

function findUser(users, id) {
  for (const user of users) {
    if (user.id === id) return user; // break + return
  }
  return null;
}

Return from a function acts like break — exits the loop and the function.

2. Filter with continue

const numbers = [1, -2, 3, -4, 5, -6];
const positives = [];

for (const num of numbers) {
  if (num < 0) continue; // skip negatives
  positives.push(num);
}
// positives = [1, 3, 5]

Skip unwanted items early, keeping the main logic clean and unindented.

3. Limit Results

const results = [];
for (const item of hugeDataset) {
  if (matches(item)) {
    results.push(item);
  }
  if (results.length >= 10) break; // stop after 10
}

Don't process the entire dataset when you only need the first N results.

4. Retry with Break

const MAX_RETRIES = 3;
let success = false;

for (let attempt = 1; attempt <= MAX_RETRIES; attempt++) {
  try {
    await fetchData();
    success = true;
    break; // success! stop retrying
  } catch (err) {
    console.log(`Attempt ${attempt} failed`);
  }
}

Try up to N times, stop as soon as one succeeds.

Frequently Asked Questions

Common questions about loop control.

// Search and stop when found: const users = ["Alice", "Bob", "Charlie", "Dave"]; let found = null; for (const user of users) { if (user === "Charlie") { found = user; break; // No need to check the rest } } console.log(found); // "Charlie"

// Skip even numbers: for (let i = 0; i < 10; i++) { if (i % 2 === 0) continue; console.log(i); // 1, 3, 5, 7, 9 } // Skip empty values: const items = ["apple", "", "banana", null, "cherry"]; for (const item of items) { if (!item) continue; // skip falsy values console.log(item); // apple, banana, cherry }

// Find first pair that sums to 10: outer: for (let i = 0; i < 5; i++) { for (let j = 0; j < 5; j++) { if (i + j === 10) { console.log(i, j); break outer; // exit BOTH loops } } }

About this chapter

About this module

Why this matters

Key topics covered

Where you'll use it

break

continue

Labels

Common Patterns

Frequently Asked Questions

About this chapter

About this module

Why this matters

Key topics covered

Where you'll use it

break

continue

Labels

Common Patterns

Frequently Asked Questions