Question

假设我有一个客户对象数组，每个客户对象都有一个发票对象数组，每个发票都有一个invoice_items数组。

给出一个invoice_item_guid-我想返回带有特定GUID的1个唯一的invoice_item对象。

我不知道客户或发票，我不想创建一堆for循环。

例如：

客户

客户编号

发票

发票编号

invoice_items

invoice_item_guid

invoice_item_id

invoice_item_qty

我打算做类似复合查找的事情，像这样：

var i: invoice_item;
i = this.customers.find(c => c.invoices).find(inv => inv.invoice_items).find(item => item.invoice_item_guid === "someguid");

充其量，我会得到一个客户对象-但我真的想更深入地研究，并获得invoice_item对象（而不是客户）。

Answer 1

我根据您的描述制作了一个虚拟数组。

以下解决方案应该可行，但可能不是最佳解决方案。

const customers = [{
    customerId: 1,
    invoices: [{
        invoiceId: 1,
        invoiceItems: [{
            invoiceItemGuid: 1
        }]
    }]
},
{
    customerId: 2,
    invoices: [{
        invoiceId: 2,
        invoiceItems: [{
            invoiceItemGuid: 2
        }]
    }]
}
]

const item = customers.flatMap(customer => customer.invoices).flatMap(invoice => invoice.invoiceItems).find(item => item.invoiceItemGuid === 2)

console.log(item)

Answer 2

您可以使用Array.reduce和Array.map提取invoice_items数组并在其上使用Array.find。

let i = this.customers
  .reduce((items, customer) => {
    return items.concat(...customer.invoices
      .map(invoice => invoice.invoice_items));
  }, [])
  .find(item => item.invoice_item_guid === 'someguid');

这是此解决方案的有效JSFiddle。

Answer 3

编辑：使用'reduce和find方法更新了答案。

const findInvoiceItem = (data) => data
  .reduce(
    (acc, curr) => [
      ...acc,
      ...curr.invoices.reduce((acc_rec, curr_rec) => [
        ...acc_rec, 
        ...curr_rec.invoice_items], [])
    ],
    []
  )
  .find(item => item.invoice_item_guid === "someguid");


const customers = [
  {
    customerid: 1,
    invoices: [
      {
        invoiceid: 1,
        invoice_items: [
          {
            invoice_item_id: 1,
            invoice_item_qty: 2,
            invoice_item_guid: "tempguid"
          }
        ]
      }
    ]
  },
  {
    customerid: 2,
    invoices: [
      {
        invoiceid: 2,
        invoice_items: [
          {
            invoice_item_id: 2,
            invoice_item_qty: 4,
            invoice_item_guid: "someguid"
          }
        ]
      }
    ]
  }
];


console.log(findInvoiceItem(customers));

打字稿返回嵌套对象参考

3 个答案: