콤마(Commas)

콤마(Commas)

• Leading commas: Nope.

• 선두의 콤마 하지마요

  // bad
  const story = [
      once
    , upon
    , aTime
  ];
  
  // good
  const story = [
    once,
    upon,
    aTime,
  ];
  
  // bad
  const hero = {
      firstName: 'Ada'
    , lastName: 'Lovelace'
    , birthYear: 1815
    , superPower: 'computers'
  };
  
  // good
  const hero = {
    firstName: 'Ada',
    lastName: 'Lovelace',
    birthYear: 1815,
    superPower: 'computers',
  };

• Additional trailing comma: Yup.

• 끝의 콤마 좋아요

  Why? This leads to cleaner git diffs. Also, transpilers like Babel will remove the additional trailing comma in the transpiled code which means you don't have to worry about the trailing comma problem in legacy browsers.

  왜? 이것은 깨끗한 git의 diffs 로 이어집니다. 또한 Babel과 같은 트랜스파일러는 transpile 하는 사이에 쓸데없는 끝의 콤마를 제거합니다. 이것은 레거시브라우저에서의 불필요한 콤마 문제를 고민할 필요가 없다는것을 의미합니다.

  // bad - git diff without trailing comma
  const hero = {
       firstName: 'Florence',
  -    lastName: 'Nightingale'
  +    lastName: 'Nightingale',
  +    inventorOf: ['coxcomb graph', 'modern nursing']
  };
  
  // good - git diff with trailing comma
  const hero = {
       firstName: 'Florence',
       lastName: 'Nightingale',
  +    inventorOf: ['coxcomb chart', 'modern nursing'],
  };
  
  // bad
  const hero = {
    firstName: 'Dana',
    lastName: 'Scully'
  };
  
  const heroes = [
    'Batman',
    'Superman'
  ];
  
  // good
  const hero = {
    firstName: 'Dana',
    lastName: 'Scully',
  };
  
  const heroes = [
    'Batman',
    'Superman',
  ];