Objects and Destructuring

Objects group related data together. Destructuring and the spread operator make working with them much less repetitive.

const course = { title: 'Modern JavaScript Essentials', lessons: 6, published: true };

const { title, lessons } = course;
console.log(title, lessons);

const student = { name: 'Ada', scores: [88, 92, 79] };
const { name, scores: [first, ...rest] } = student;
console.log(name, first, rest);

const upgraded = { ...course, lessons: course.lessons + 1 };
console.log(upgraded);
console.log('original untouched:', course.lessons);

What's happening

• const { title, lessons } = course pulls properties straight out of an object into variables.
• ...rest collects whatever is left over into a new array (or object).
• { ...course, lessons: 7 } copies every property from course into a brand-new object, then overrides lessons, the original object is never mutated.