Demo: An inherited notice

An inherited notice

A specialized notice reuses a base notice’s label. extends connects the classes; super(label) initializes the parent before using this. The child overrides describe() while retaining the common part via super.describe().

javascript

class Notice {
  constructor(label) { this.label = label; }
  describe() { return `Notice: ${this.label}`; }
}
class ScheduleNotice extends Notice {
  constructor(label, hour) {
    super(label);
    this.hour = hour;
  }
  describe() { return `${super.describe()} at ${this.hour}`; }
}
const notice = new ScheduleNotice("Garden club", "10:00");
console.log(notice instanceof Notice);
console.log(notice.describe());

What to notice

Change the hour and run again. Next, use inheritance for shapes that calculate their areas.

Demo: An inherited notice

An inherited notice

javascript

class Notice {
  constructor(label) { this.label = label; }
  describe() { return `Notice: ${this.label}`; }
}
class ScheduleNotice extends Notice {
  constructor(label, hour) {
    super(label);
    this.hour = hour;
  }
  describe() { return `${super.describe()} at ${this.hour}`; }
}
const notice = new ScheduleNotice("Garden club", "10:00");
console.log(notice instanceof Notice);
console.log(notice.describe());

What to notice

Change the hour and run again. Next, use inheritance for shapes that calculate their areas.