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

const person = {
  firstName: 'Lydia',
  lastName: 'Hallie',
  pet: {
    name: 'Mara',
    breed: 'Dutch Tulip Hound'
  },
  getFullName() {
    return `${this.firstName} ${this.lastName}`;
  }
};

console.log(person.pet?.name);
console.log(person.pet?.family?.name);
console.log(person.getFullName?.());
console.log(member.getLastName?.());

const groceries = ['banana', 'apple', 'peanuts'];

if (groceries.indexOf('banana')) {
  console.log('We have to buy bananas!');
} else {
  console.log(`We don't have to buy bananas!`);
}

const config = {
  languages: [],
  set language(lang) {
    return this.languages.push(lang);
  }
};

console.log(config.language);

const name = 'Lydia Hallie';

console.log(!typeof name === 'object');
console.log(!typeof name === 'string');

const add = x => y => z => {
  console.log(x, y, z);
  return x + y + z;
};

add(4)(5)(6);