JavaScript Loop Control — Interview Questions & Answers

Ques: What is loop control in JavaScript?

Ans: Loop control statements are used to change the normal flow of a loop — to exit early, skip iterations, or control nested loops.

Main loop control statements:

• break
• continue
• label (used with break/continue)

Ques: What is the break statement in JavaScript?

Ans: The break statement is used to exit a loop immediately, even if the loop condition is still true.

Example:

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

Output:

1
2

Ques: What is the continue statement?

Ans: The continue statement skips the current iteration and moves to the next loop cycle.

Example:

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

Output:

1
2
4
5

Ques: What is the difference between break and continue?

Example:

for (let i = 1; i <= 5; i++) {
  if (i === 3) continue; // skip 3
  if (i === 4) break;    // stop at 4
  console.log(i);
}

Output:

1
2

Ques: What are labelled statements in JavaScript?

Ans: A label gives a name to a loop (or block) and allows break or continue to refer to specific outer loops in nested structures.

Syntax:

labelName: statement

Example:

outerLoop:
for (let i = 1; i <= 3; i++) {
  for (let j = 1; j <= 3; j++) {
    if (i === 2 && j === 2) break outerLoop;
    console.log(`i=${i}, j=${j}`);
  }
}

Output:

i=1, j=1
i=1, j=2
i=1, j=3
i=2, j=1

Ques: Can continue be used with labels?

Ans: Yes, When using nested loops, continue with a label allows jumping to the next iteration of the labeled loop.

Example:

outer:
for (let i = 1; i <= 3; i++) {
  for (let j = 1; j <= 3; j++) {
    if (j === 2) continue outer;
    console.log(`i=${i}, j=${j}`);
  }
}

Output:

i=1, j=1
i=2, j=1
i=3, j=1

Ques: When should you use labelled statements?

Ans: Use labels only when absolutely necessary — like when controlling nested loops where simple break or continue isn’t enough.

Avoid them in simple loops — they reduce readability and can confuse flow.

Ques: Are break and continue allowed outside loops or switch statements?

Ans: No, Both break and continue can only be used inside:

• Loops (for, while, do...while)
• switch statements (for break only)

Ques: Can you use return instead of break in functions?

Ans: Yes, inside a function, return immediately exits the function — similar to how break exits a loop.

However:

• break only affects loops or switch
• return affects function execution

Ques: What are best practices for loop control statements?

• Use break and continue for clarity, not complexity.
• Avoid deeply nested loops — refactor with functions.
• Use labels sparingly and name them clearly.
• Ensure loop conditions and exit logic are well-defined.