如何按升序和降序排序Angular 6

Question

我想按升序和降序对方法中的数据进行排序。 这是我的方法。

public get students(): Student[] {
    return this._dashboardService.account.students;
}

这是我的component.html代码

<li *ngFor="let stud of students">
    <div class="{{stud == selectedStudent && highlightStudent ? 'hoveffect' : ''}}">
        <div class="hovlink">
            <a (click)="setStudent(stud)">
                <img [src]="stud.imageUrl ? getStudentFaceImage(stud.imageUrl) : tempDpImage" />
                <!--<span>{{stud.firstName}}</span>-->
            </a>
        </div>
        <h4>{{stud.schoolId}}</h4>              
    </div>
</li>

如果您知道解决方法，请帮助我。

这是学生班。

export class Student {
  public userID: number;
  public firstName: string;
  public lastName: string;
  public schoolId: number;
  public schoolName: string;
  public classId: number;
  public className: string;
  public sectionId: number;
  public sectionName: string;
  public currencyCode: string;
  public favImageWithoutCorselCount: number;
  public NonfavImageWithoutCorselCount: number;
  public photos: listData<any>;
  public products: listData<any>;
  public packages: listData<any>;
  public orders: any;
  public downloads: listData<any>;
  public offers: listData<any>;
  public cart: any;
  public supportDetail: SupportDetail;
  public timeStamp: any;
  public isSibling: number;
  public EventName: string;
  public QrCode: string;
}