Angular typeScript 嵌套数组不可迭代？

Question

我有一个像这样的模型类“EventDeatails”

export class EventDetails {
  id: string;
  title: string;
  club: string;
  des: string;
  img: string;
  date: string;
  status: number;
}

然后我从 firebase 为其分配值，如下所示

showingEventList: EventDetails[];

this.eventDetails.getOldEvents().subscribe(actionArray => {
  this.showingEventList = actionArray.map(item => {
    return {
      id: item.payload.doc.id,
      ...item.payload.doc.data()
    } as EventDetails ;
  });
});

现在我只需要将该对象的 Club 属性添加到另一个名为的数组中clubs[] 我是这样做的

for ( const item  of this.showingEventList ) {
      this.clubs.push(item.club);
    }

但控制台显示有一个错误：-“ showingEventList is not iterable”我该如何解决这个问题？？？