Breaking a Loop

We can break out of a loop while it is running.

The break keyword stops a loop. The rest of the code inside the loop doesn't run. The code keeps running after the loop.

Here's a basic example:

let i = 0;
while (i < 10) {
  console.log(i);
  if (i === 5) {
    break;
  }
  i++;
}

Once i reaches 5, the loop breaks. The value of i will never reach 10.

Break inside a function

Here's an example of breaking out of a loop inside a function:

function getFirstWord(string) {
  let result = '';
  for (let i = 0; i < string.length; i++) {
    let character = string[i];
    if (character === ' ') {
      break;
    }
    result += character;
  }
  return result;
}
getFirstWord('The fox jumped over the lazy dog');

Returning out of a loop

We can also use the return keyword to exit a loop.

Remember that we can only return from inside a function:

function getFirstWord(string) {
  let result = '';
  for (let i = 0; i < string.length; i++) {
    let character = string[i];
    if (character === ' ') {
      return result;
    }
    result += character;
  }
  return result;
}
getFirstWord('The fox jumped over the lazy dog');

Since return stops the rest of the code inside the function from running, it stops the loop as well.