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:

Ques: What is the difference between break and continue?

Feature	`break`	`continue`
Purpose	Exits the loop completely	Skips the current iteration
Control Flow	Jumps out of the loop	Moves to next iteration
Use Case	When loop should stop	When one condition should be ignored

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.