What will be the output of the following code, if there aren't any items present in the storage objects at the beginning?
window.localStorage.setItem('1', 'one');
window.localStorage.setItem('2', 'two');
window.localStorage.setItem('3', 'three');
window.localStorage.setItem('4', 'four');
window.sessionStorage.setItem('5', 'five');
window.localStorage.setItem('6', 'six');
window.localStorage.length;