섹션 2 Javascript Fundamentals part 2 - Dot vs Bracket Notation

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// Dot vs. Bracket Notation
const jonas = {
  firstName: 'Jonas',
  lastName: 'Schmedtmann',
  age: 2037 - 1991,
  job: 'teacher',
  friends: ['Michael', 'Peter', 'Steven']
};
console.log(jonas);

console.log(jonas.lastName);
console.log(jonas['lastName']);

const nameKey = 'Name';
console.log(jonas['first' + nameKey]);
console.log(jonas['last' + nameKey]);

// console.log(jonas.'last' + nameKey)

const interestedIn = prompt('What do you want to know about Jonas? Choose between firstName, lastName, age, job, and friends');

if (jonas[interestedIn]) {
  console.log(jonas[interestedIn]);
} else {
  console.log('Wrong request! Choose between firstName, lastName, age, job, and friends');
}

jonas.location = 'Portugal';
jonas['twitter'] = '@jonasschmedtman';
console.log(jonas);

 

jonas.lastName와 jonas['lastName']은 똑같이 jonas 옵션안의 lastName의 값을 불러오는 기능을 한다