Can default Appear Anywhere in a JavaScript switch Statement?

Typically, the default clause appears at the end of a switch statement, and is executed when none of the cases match the value of the provided expression:

switch (expression) {
  case 'foo':
    // ...
    break;
  case 'bar':
    // ...
    break;
  default:
    // ...
    break;
}

default clause can, however, be placed anywhere within the switch statement, and will still be executed only in case none of the other cases match:

const expression = 'non-existent';

switch (expression) {
  case 'foo':
    console.log('foo');
    break;

  default:
    console.log('default');
    break;

  case 'bar':
    console.log('bar');
    break;
}

// output: 'default'

If you don't add a break after the default, then it will fall-through if other cases appear after it (as shown in the following code):

const expression = 'non-existent';

switch (expression) {
  case 'foo':
    // ...
    break;

  default:
    console.log('default');

  case 'bar':
    console.log('bar');
    break;
}

// output:
// 'default'
// 'bar'