Here are some essential topics covered in the book:

const [x, y, z ] = [1, y: 2, z: 3 ]; console.log(x); // 1 console.log(y); // 2 console.log(z); // 3

const name, age, address: street, city = getUser(); console.log(name); // John console.log(age); // 30 console.log(street); // 123 Main St console.log(city); // Anytown