In JavaScript, the break
and continue
statements are used to control the flow of loops (for
, while
, and do...while
). They provide mechanisms to exit or skip iterations based on specific conditions.
The break
statement terminates the current loop immediately and exits the loop entirely. After the break
statement is executed, the control flow moves to the statement following the loop.
When you want to stop the loop once a specific condition is met.
break;
for (let i = 1; i <= 5; i++) {
if (i === 3) {
break; // Exit the loop when i equals 3
}
console.log(i);
}
// Output: 1, 2
In this example:
- The loop terminates completely when
i
is3
.
The continue
statement skips the rest of the current iteration and moves to the next iteration of the loop. It does not terminate the loop, only the current iteration.
When you want to skip specific iterations of a loop based on a condition.
continue;
for (let i = 1; i <= 5; i++) {
if (i === 3) {
continue; // Skip the iteration when i equals 3
}
console.log(i);
}
// Output: 1, 2, 4, 5
In this example:
- The loop skips the
console.log
statement wheni
equals3
and continues with the next iteration.
Feature | break |
continue |
---|---|---|
Effect on Loop | Terminates the loop entirely. | Skips the current iteration. |
Control Flow | Moves to the statement after the loop. | Moves to the next iteration. |
Usage | To exit the loop under certain conditions. | To skip specific iterations. |
for (let i = 1; i <= 10; i++) {
if (i === 3) {
continue; // Skip the iteration for i = 3
}
if (i === 7) {
break; // Exit the loop completely when i = 7
}
console.log(i);
}
// Output: 1, 2, 4, 5, 6
const numbers = [1, 2, 3, 4, 5];
const target = 3;
for (let i = 0; i < numbers.length; i++) {
if (numbers[i] === target) {
console.log(`Found ${target} at index ${i}`);
break; // Stop searching once the target is found
}
}
const numbers = [1, 2, 3, 4, 5];
for (let num of numbers) {
if (num % 2 === 0) {
continue; // Skip even numbers
}
console.log(num);
}
// Output: 1, 3, 5
- The
break
statement is used to terminate a loop when a specific condition is met. - The
continue
statement is used to skip certain iterations without stopping the entire loop. - Both statements provide flexibility in controlling the flow of loops, making them essential tools for writing efficient and concise code in JavaScript.