Arrays 键入脚本合并2个数组，如果它们具有相同的id，则增加数量

我正在处理Angular 8项目，我想将2个数组合并为1，如果它们在对象中具有相同的值，则增加数量。我自己试过几次，效果并不好

mergedOrderList: any[]= [];

lstOldOrder: any[] = [
{id: "", products_id: "", qty: 1, ...},
{id: "", products_id: "", qty: 1, ...},
{id: "", products_id: "", qty: 1, ...},];

lstNewOrder: any[] = [
{id: "", products_id: "", qty: 1, ...},
{id: "", products_id: "", qty: 1, ...},
{id: "", products_id: "", qty: 1, ...},];

lstNewOrder.forEach(newOrder => {

    let isDubplicated: boolean = false;

    lstOldOrder.forEach(oldOrder => {

      if (newOrder.products_id == oldOrder.products_id) {
        oldOrder.qty += newOrder.qty;
        isDubplicated = true;
        mergedOrderList.push(oldOrder);
      }
    });

    if (!isDubplicated) {
      mergedOrderList.push(newOrder)
    }

  });

---

我是这样做的，当它们都有相同的产品id时，它们工作。但是当新订单没有产品id时，它们会跳过我的旧订单，只向列表中添加新订单。我不太确定我做对了。谢谢

请看问题在于，如果 新列表项的

产品\u id

与旧列表中的任何项匹配

因此，如果

lstNewOrder

相反，你应该做的是：

将项目添加到

mergedOrderList

中，但如果存在匹配项，则增加数量

mergedOrderList = [];

lstOldOrder = [
  { id: "1", products_id: "", qty: 1 },
  { id: "2", products_id: "", qty: 1 },
  { id: "3", products_id: "", qty: 1 },
];

lstNewOrder = [
  { id: "4", products_id: "", qty: 1 },
  { id: "5", products_id: "", qty: 1 },
  { id: "1", products_id: "", qty: 1 },
];

lstNewOrder.forEach((newOrder) => {
  Oindex = -1;
  lstOldOrder.forEach((item, index) => {
    if (item.id == newOrder.id) {
      Oindex = index; // Getting the Index of that item in old array.
    }
  });

  if (Oindex != -1) { // if that item was in old Array
    newOrder.qty += lstOldOrder[Oindex].qty; // Increase Quantity in newOrderItem
    lstOldOrder.splice(Oindex, 1); // Delete that Item from OldArray
  }
  mergedOrderList.push(newOrder); // Add the Item in Merged
});

mergedOrderList.concat(lstOldOrder); // Finally add all the remaining Items

代码中的所有边缘情况都没有得到正确处理，对此表示抱歉。 请随意编辑我的答案，它可能会帮助其他人