basic-class-with-destructuring.js

class Person {
  constructor({ firstName, lastName }) {
    this.firstName = firstName || 'John';
    this.lastName = lastName || 'Doe';
  }

  getFullName() {
    return this.firstName + ' ' + this.lastName;
  }
}

console.log(new Person({}).getFullName());
console.log(new Person({ lastName: 'Smith' }).getFullName());  // John Smith