WebDEV. Страница 28

'use strict';

let [firstName, lastName] = ["Илья", "Кантор"];

alert(firstName); // Илья
alert(lastName);  // Кантор

'use strict';

// первый и второй элементы не нужны
let [, , title] = "Юлий Цезарь Император Рима".split(" ");

alert(title); // Император

function sum(x, y, z) {
  return x + y + z;
}

const numbers = [1, 2, 3];

console.log(sum(...numbers));
// expected output: 6

console.log(sum.apply(null, numbers));
// expected output: 6

const foo = null ?? 'default string';
console.log(foo);
// expected output: "default string"

const baz = 0 ?? 42;
console.log(baz);
// expected output: 0

const adventurer = {
  name: 'Alice',
  cat: {
    name: 'Dinah'
  }
};

const dogName = adventurer.dog?.name;
console.log(dogName);
// expected output: undefined

console.log(adventurer.someNonExistentMethod?.());
// expected output: undefined