solution.md

Using a question mark operator '?':

function checkAge(age) {
  return (age > 18) ? true : confirm('Did parents allow you?');
}

Using OR || (the shortest variant):

function checkAge(age) {
  return (age > 18) || confirm('Did parents allow you?');
}

Note that the parentheses around age > 18 are not required here. They exist for better readabilty.