将 object 的嵌套数组转换为简单的 Json object javascript

Question

hi need some help regarding normalizing array of objects. i have this nested array which has some json objects and those objects have array.

  [
   {
    customerId: 20
    customerName: "customer 1"
    orderItems: [
       {
        productId: '23'
        productName: 'ice cream'
        price: '200'
        },
      ....
     ] 
   },
    customerId: 21
    customerName: "customer 2"
    orderItems: [
       {
        productId: '47'
        productName: 'bottle'
        price: '60'
        },
       {
        productId: '48'
        productName: 'shake'
        price: '544'
        },
       ....
     ] 
   },
 ]

i want it like this

    [
     {
        customerId: 20
        customerName: "customer 1",
        productId: '23'
        productName: 'ice creems'
        price: '200',
        ....
     },
      {
        customerId: 21
        customerName: "customer 2",
        productId: '47'
        productName: 'bottle'
        price: '60',
        ....
      },
       {
        customerId: 21
        customerName: "customer 2",
        productId: '48'
        productName: 'shake'
        price: '544',
        ....
       }
     ]

Can someone help me in this regard? i have tried map operator but i couldn't loop through inner array. thanks

Answer 1

You could take a Array#flatMap approach and take the denormalized data.

 var data = [{ customerId: 20, customerName: "customer 1", orderItems: [{ productId: '23', productName: 'ice cream', price: '200' }] }, { customerId: 21, customerName: "customer 2", orderItems: [{ productId: '47', productName: 'bottle', price: '60' }, { productId: '48', productName: 'shake', price: '544' }] }], denormalized = data.flatMap(({ orderItems, ...customer }) => orderItems.map(order => ({...customer, ...order }))); console.log(denormalized);

 .as-console-wrapper { max-height: 100%;important: top; 0; }

Answer 2

You can use .map() and .flat() methods to get the desired output:

 const data = [{ customerId: 20, customerName: "customer 1", orderItems: [{ productId: '23', productName: 'ice cream', price: '200' }] }, { customerId: 21, customerName: "customer 2", orderItems: [{ productId: '47', productName: 'bottle', price: '60' }, { productId: '48', productName: 'shake', price: '544' }] }]; const result = data.map( ({orderItems, ...rest}) => orderItems.map(o => Object.assign({}, rest, o)) ).flat(); console.log(result);

 .as-console-wrapper { max-height: 100%;important: top; 0; }