Arrays 如何反转Firestore的数据阵列？角度6

我想将数据从新数据反转为旧数据，我在object ex:[1,2,3,4,5]中设置了idNumber

注意

您可以在收款呼叫中使用orderBy

显示了如何专门使用orderBy

使用服务器对数据进行排序可以提高客户端性能

listItemAds() {
        this.itemList = this.afs.collection<Class>('Collection');

        this.itemList.snapshotChanges().subscribe(list => {
        this.itemArray = [];
        list.forEach(action => {
        const data = action.payload.doc.data() as Class;
        this.itemArray.push(data);
-->  this.itemArray.reverse(); // I try use this.itemArray.reverse(data.idNumber) ==> error
           });
         });
         console.log(this.itemArray);

      }

this.itemList = this.afs.collection<Class>(
    'Collection',
    ref => ref.orderBy('idNumber', 'desc')
);
this.itemList.subscribe(list => {
    console.log(list);
});