Create a new arrangement of objects and group repeating objects

Question

I have an array of objects like this

[
 { id: 1, note: "TEST", member_id: 1, updated_at: "2021-04-08T15:59:08.210754", product_id: 1,
 product: { id: 1, name: "Testing",},},
 {id: 2, note: "", member_id: 1, updated_at: "2021-04-08T18:07:19.712304", product_id: 5,
 product: { id: 5, name: "Insurance"}, },
 { id: 3, note: "One note", member_id: 1, updated_at: "2021-04-08T18:11:26.444726", product_id: 5, 
 product: { id: 5, name: "Insurance" },},
{ id: 4, note: "sadad", member_id: 1, updated_at: "2021-04-08T18:28:59.8435", product_id: 5, product: 
 { id: 5, name: "Insurance" }, },
];

I have to represent it in a table where it can be grouped by product name and the number of objects that have the same product is counted as well as the last update of any of them is shown.

It should look like this

Try to use reduce but I could not advance much because I did not understand it and I used grouby with lodash but I could not advance more than that

I need it to stay like this

[
 {product: "Insurance", 
 quantity: 3, 
 updated_at: "2021-04-08", 
 sales: [ 
         { id: 2, 
           note: "", 
           member_id: 1, 
           updated_at: "2021-04-08", 
           product_id: 5
         }, 
         { id: 3, 
           note: "One note", 
           member_id: 1, 
           updated_at: "2021-04-08", 
           product_id: 5
         }, 
         { id: 4, 
           note: "sadad", 
           member_id: 1, 
           updated_at: "2021-04-08",
           product_id: 5
         }
        ]
  },
  {product: "Testing", 
   quantity: 1, 
   updated_at: "2021-04-08", 
   sales: [ 
           {id: 1, 
            note: "TEST", 
            member_id: 1, 
            updated_at: "2021-04-08", 
            product_id: 1,} 
          ]},
]

I tried to use reduce but it was not what I expected and I did not understand it much either

array.reduce((acc, it) => {
acc[it.product.name] = acc[it.product.name] + 1 || 1;
return acc;
}, {});

Maybe this will be of help to you. https://stackoverflow.com/questions/40774697/how-to-group-an-array-of-objects-by-key — RGA, Apr 12 '21 at 13:43
you haven't shown any attempt, please provide it. Aslo please provide the final JSON structure you want — EugenSunic, Apr 12 '21 at 13:48
I already completed the missing data, could you guide me how to solve the problem? @EugenSunic — Jorge Barcos, Apr 12 '21 at 14:17
Does this answer your question? [Most efficient method to groupby on an array of objects](https://stackoverflow.com/questions/14446511/most-efficient-method-to-groupby-on-an-array-of-objects) — pilchard, Apr 12 '21 at 14:20

score 2 · Answer 1 · answered Apr 12 '21 at 14:47

const sales = [
  {
    "id": 1,
    "note": "TEST",
    "member_id": 1,
    "updated_at": "2021-04-08T15:59:08.210754",
    "product_id": 1,
    "product": {
      "id": 1,
      "name": "Testing"
    }
  },
  {
    "id": 2,
    "note": "",
    "member_id": 1,
    "updated_at": "2021-04-08T18:07:19.712304",
    "product_id": 5,
    "product": {
      "id": 5,
      "name": "Insurance"
    }
  },
  {
    "id": 3,
    "note": "One note",
    "member_id": 1,
    "updated_at": "2021-04-08T18:11:26.444726",
    "product_id": 5,
    "product": {
      "id": 5,
      "name": "Insurance"
    }
  },
  {
    "id": 4,
    "note": "sadad",
    "member_id": 1,
    "updated_at": "2021-04-08T18:28:59.8435",
    "product_id": 5,
    "product": {
      "id": 5,
      "name": "Insurance"
    }
  }
];


const newObject = sales.reduce((allProducts, singleSale) => {
  if(allProducts.has(singleSale.product.name)){

    const product = allProducts.get(singleSale.product.name);
    
    allProducts.set(singleSale.product.name, {
      ...product,
      quantity: product.sales.length + 1,
      sales: [...product.sales, singleSale]
    });

  } else {
    allProducts.set(singleSale.product.name, {
      product: singleSale.product.name,
      quantity: 1, 
      sales: [singleSale]
    })
  }
  
  return allProducts;
}, new Map());

console.log([...newObject.values()])

https://jsbin.com/govocoyeri/edit?js,console

This should give you the desired result.

EugenSunic · Accepted Answer · 2021-04-12T15:37:49.293

You can try something like this, it will should give you the desired output.

const list = [{
    id: 1,
    note: "TEST",
    member_id: 1,
    updated_at: "2021-04-08T15:59:08.210754",
    product_id: 1,
    product: {
      id: 1,
      name: "Testing",
    },
  },
  {
    id: 2,
    note: "",
    member_id: 1,
    updated_at: "2021-04-08T18:07:19.712304",
    product_id: 5,
    product: {
      id: 5,
      name: "Insurance"
    },
  },
  {
    id: 3,
    note: "One note",
    member_id: 1,
    updated_at: "2021-04-08T18:11:26.444726",
    product_id: 5,
    product: {
      id: 5,
      name: "Insurance"
    },
  },
  {
    id: 4,
    note: "sadad",
    member_id: 1,
    updated_at: "2021-04-08T18:28:59.8435",
    product_id: 5,
    product: {
      id: 5,
      name: "Insurance"
    },
  },
];

const result = list.reduce((acc, x) => {
  const index = acc.findIndex(obj => obj.product === x.product.name);
  const salesObj = {
    id: x.id,
    note: x.note,
    member_id: x.member_id,
    updated_at: x.updated_at,
    product_id: x.product_id
  };
  if (index < 0) {
    acc = [...acc, {
      product: x.product.name,
      quantity: 1,
      updated_at: x.updated_at,
      sales: [salesObj]
    }];
    return acc;
  }
  acc[index].updated_at = x.updated_at;
  acc[index].quantity++;
  acc[index].sales.push(salesObj);
  return acc;
}, []);

console.log(result)

This is the answer I was looking for, I wanted to ask you how I could put the last update_at of the salts in the new object? — Jorge Barcos, Apr 12 '21 at 15:14
{"product": "Insurance", "quantity": 3, "updated_at": "2021-04-08", sales: [{...}]} — Jorge Barcos, Apr 12 '21 at 15:27
@JorgeBarcos update then the existing object to get the latest value/update like this ```acc[index].updated_at = x.updated_at; ```Added the change, check it out — EugenSunic, Apr 12 '21 at 15:38

score 1 · Answer 3 · answered Apr 12 '21 at 14:41

Use _.gropyBy to group the items, and use _.toPairs to get key-value pair of an object and then use map to customize the objects in a group

here list is the input array

var result = _.toPairs(_.groupBy(list, 'product.name'))
 .map(([product, sales]) => {
    const quantity = sales.length;
        return {
            product, 
            quantity, 
            updated_at: sales[quantity-1].updated_at, 
            sales: sales.map(item => _.omit(item, 'product')) 
        }
    });
console.log(result)

Create a new arrangement of objects and group repeating objects

3 Answers3