Bad:
const DAYS_IN_WEEK = 7;
const daysInMonth = 30;const songs = ['Back In Black', 'Stairway to Heaven', 'Hey Jude'];
const Artists = ['ACDC', 'Led Zeppelin', 'The Beatles'];function eraseDatabase() {}
function restore_database() {}class animal {}
class Alpaca {}Good:
const DAYS_IN_WEEK = 7;
const DAYS_IN_MONTH = 30;const SONGS = ['Back In Black', 'Stairway to Heaven', 'Hey Jude'];
const ARTISTS = ['ACDC', 'Led Zeppelin', 'The Beatles'];function eraseDatabase() {}
function restoreDatabase() {}class Animal {}
class Alpaca {}

Bad:
//顺序乱
class PerformanceReview {constructor(employee) {this.employee = employee;}lookupPeers() {return db.lookup(this.employee, 'peers');}lookupManager() {return db.lookup(this.employee, 'manager');}getPeerReviews() {const peers = this.lookupPeers();// ...
  }perfReview() {this.getPeerReviews();this.getManagerReview();this.getSelfReview();}getManagerReview() {const manager = this.lookupManager();}getSelfReview() {// ...
  }
}const review = new PerformanceReview(employee);
review.perfReview();Good:
//顺序自上而下，调用函数在被调用函数上面
class PerformanceReview {constructor(employee) {this.employee = employee;}perfReview() {this.getPeerReviews();this.getManagerReview();this.getSelfReview();}getPeerReviews() {const peers = this.lookupPeers();// ...
  }lookupPeers() {return db.lookup(this.employee, 'peers');}getManagerReview() {const manager = this.lookupManager();}lookupManager() {return db.lookup(this.employee, 'manager');}getSelfReview() {// ...
  }
}const review = new PerformanceReview(employee);
review.perfReview();