獲取價格金額乘以嵌套數量的總和 arrays

Question

我有這樣的嵌套對象數組：

[
  {
    tasks: [
      {
        requestTaskId: 'be6ee458-8ef0-11ec-912a-3d12c29b6342',
        price: 5,
      },
      {
        requestTaskId: 'be6ee502-8ef0-11ec-b81a-3d12c29b6342',
        price: 5,
      },
    ],
    request: {
      tasks: [
        {
          id: 'be6ee458-8ef0-11ec-912a-3d12c29b6342',
          quantity: 10,
        },
        {
          id: 'be6ee502-8ef0-11ec-b81a-3d12c29b6342',
          quantity: 10,
        },
      ],
    },
  },
];

我需要總結所有任務的價格和數量，還通過tasks.requestTaskId === request.tasks.id條件檢查/匹配。

結果應為 (10 * 5) + (10 * 5) = 100。

如何使用map / find / reduce得到這個？ 想不出更好的幫手來實現這一點，只是不知道如何結合一切。

這是我試過的：

  array.map((item) => ({
      ...item,
      ...item.request.tasks.find((requestTask) => ({
        ...requestTask,
        ...item.tasks.find(({ requestTaskId }) => requestTaskId === requestTask.id),
      })),
    }))
    .map(({ amount, quantity})) => ({
      total: amount * quantity,
    });

Answer 1

這是您給定數據的示例，假設多個對象出現在頂層 object 中：

const data = [{
    tasks: [{
        requestTaskId: 'be6ee458-8ef0-11ec-912a-3d12c29b6342',
        price: 5,
    },
    {
        requestTaskId: 'be6ee502-8ef0-11ec-b81a-3d12c29b6342',
        price: 5,
    },
    ],
    request: {
        tasks: [{
            id: 'be6ee458-8ef0-11ec-912a-3d12c29b6342',
            quantity: 10,
        },
        {
            id: 'be6ee502-8ef0-11ec-b81a-3d12c29b6342',
            quantity: 10,
        },
        ],
    },
},];



// function for calculating the total of one object holding tasks and request props.
function calculateTotalPrice(entity) {

    // iterate through all tasks and "reduce" them to one number :)
    return entity.tasks.reduce((total, task) => {

        // Search for a request with the same id!.
        const request = entity.request.tasks.find(request => request.id === task.requestTaskId)

        if (request) {
            return total + (request.quantity * task.price)
        }

        // If no price is found, return current total and log something!.
        console.log('No price found for task:', task)
        return total
    }, 0)
}


// With your object you can now reduce this aswell for getting the grand 
// total over all objects..
const totalPrice = data.reduce((grandTotal, entity) => {
    return grandTotal + calculateTotalPrice(entity)
}, 0)

console.log('totalPrice:', totalPrice)

Answer 2

您可以使用Array.reduce()對所有任務的總價格求和，首先調用輸入數組，然后調用任務。

如果沒有找到任務的requestTask ，我們將簡單地保留總數不變。 如果您覺得這能更好地反映您的用例，您可以更改此行為以拋出錯誤。

我們將其包裝在getTotalSum() function 中。

 let input1 = [ { tasks: [ { requestTaskId: 'be6ee458-8ef0-11ec-912a-3d12c29b6342', price: 5, }, { requestTaskId: 'be6ee502-8ef0-11ec-b81a-3d12c29b6342', price: 5, }, ], request: { tasks: [ { id: 'be6ee458-8ef0-11ec-912a-3d12c29b6342', quantity: 10, }, { id: 'be6ee502-8ef0-11ec-b81a-3d12c29b6342', quantity: 10, }, ], }, }, ]; let input2 = [ { tasks: [ { requestTaskId: '4a0cc1d8-9720-48c4-9678-3372c20ff7c3', price: 10, }, { requestTaskId: '6c178a61-e9aa-45bf-bcde-1a52bcd29205', price: 1, }, ], request: { tasks: [ { id: '4a0cc1d8-9720-48c4-9678-3372c20ff7c3', quantity: 2, }, { id: '6c178a61-e9aa-45bf-bcde-1a52bcd29205', quantity: 3, }, ], }, }, ]; function getTotalSum(input) { return input.reduce((total, { tasks, request }) => { return tasks.reduce((total, task) => { const requestTask = request.tasks.find(({ id }) => id === task.requestTaskId); total += requestTask? task.price * requestTask.quantity: 0; return total; }, total) }, 0) } console.log('Sum1:', getTotalSum(input1)) console.log('Sum2:', getTotalSum(input2))

Answer 3

如果您的 object 的順序如圖所示，每個任務按索引行進相應的請求，那么使用.map()和.reduce()方法將實現您的目標：

const total = orders.map(order => order.tasks.reduce(
    (tot, prod, index) => tot + prod.price * order.request.tasks[index].quantity, 0
));

console.log( total );

演示

 const orders = [{ tasks: [{ requestTaskId: 'be6ee458-8ef0-11ec-912a-3d12c29b6342', price: 5, }, { requestTaskId: 'be6ee502-8ef0-11ec-b81a-3d12c29b6342', price: 5, }, ], request: { tasks: [{ id: 'be6ee458-8ef0-11ec-912a-3d12c29b6342', quantity: 10, }, { id: 'be6ee502-8ef0-11ec-b81a-3d12c29b6342', quantity: 10, }, ], }, },{ tasks: [{ requestTaskId: 'dabee458-8ef0-11ec-912a-3d12c29b6342', price: 15, }, { requestTaskId: 'dabee502-8ef0-11ec-b81a-3d12c29b6342', price: 15, }, ], request: { tasks: [{ id: 'dabee458-8ef0-11ec-912a-3d12c29b6342', quantity: 15, }, { id: 'dabee502-8ef0-11ec-b81a-3d12c29b6342', quantity: 50, }, ], }, }]; const total = orders.map(order => order.tasks.reduce( (tot, prod, index) => tot + prod.price * order.request.tasks[index].quantity, 0 )); console.log( total );