weekdays.enum.ts

class WeekDays {
  private static map: Map<number, WeekDays> = new Map();

  public static readonly SUNDAY = WeekDays.build(0, 'SUNDAY');
  public static readonly MONDAY = WeekDays.build(1, 'MONDAY');
  public static readonly TUESDAY = WeekDays.build(2, 'TUESDAY');
  public static readonly WEDNESDAY = WeekDays.build(3, 'WEDNESDAY');
  public static readonly THURSDAY = WeekDays.build(4, 'THURSDAY');
  public static readonly FRIDAY = WeekDays.build(5, 'FRIDAY');
  public static readonly SATURDAY = WeekDays.build(6, 'SATURDAY');

  private constructor (
    public readonly code: number,
    public readonly key: string
  ) { }

  private weekends(): Array<WeekDays> {
    return [WeekDays.SATURDAY, WeekDays.SUNDAY]
  }

  public equals(weekDay: WeekDays) {
    return this.code === weekDay.code;
  }

  public isWeekday(): boolean {
    return !this.isWeekend();
  }

  public isWeekend(): boolean {
    return this.weekends().some((weekend: WeekDays) => weekend.equals(this));
  }

  public static build(code: number, key: string) {
    const enumerator = this.map.get(code);
    if (enumerator) {
      throw new Error('Code is not available');
    } else {
      const weekDay = new WeekDays(code, key);
      this.map.set(code, weekDay);
      return weekDay;
    }
  }
}

weekdays2.enum.ts

class WeekDays {
  private static map: Map<number, WeekDays> = new Map();

  public static readonly SUNDAY = WeekDays.build(0, 'SUNDAY');
  public static readonly MONDAY = WeekDays.build(1, 'MONDAY');
  public static readonly TUESDAY = WeekDays.build(2, 'TUESDAY');
  public static readonly WEDNESDAY = WeekDays.build(3, 'WEDNESDAY');
  public static readonly THURSDAY = WeekDays.build(4, 'THURSDAY');
  public static readonly FRIDAY = WeekDays.build(5, 'FRIDAY');
  public static readonly SATURDAY = WeekDays.build(6, 'SATURDAY');

  private constructor (
    public readonly code: number,
    public readonly key: string
  ) { }

  private weekends(): Array<WeekDays> {
    return [WeekDays.SATURDAY, WeekDays.SUNDAY]
  }

  public equals(weekDay: WeekDays) {
    return this.code === weekDay.code;
  }

  public isWeekday(): boolean {
    return !this.isWeekend();
  }

  public isWeekend(): boolean {
    return this.weekends().some((weekend: WeekDays) => weekend.equals(this));
  }

  public static getEnumByCode(code: number) {
    return this.map.get(code);
  }

  public static build(code: number, key: string) {
    const enumerator = this.map.get(code);
    if (enumerator) {
      throw new Error('Code is not available');
    } else {
      const weekDay = new WeekDays(code, key);
      this.map.set(code, weekDay);
      return weekDay;
    }
  }
}


// console.log(WeekDays.FRIDAY.isWeekend())
// console.log(WeekDays.FRIDAY.isWeekday())

console.log(WeekDays.FRIDAY.equals(WeekDays.FRIDAY))
// console.log(WeekDays.FRIDAY.equals({code: 5, key: 'asdf'}))
console.log(WeekDays.getEnumByCode(0))
console.log(WeekDays.getEnumByCode(6))
console.log(WeekDays.getEnumByCode(10))