在对象 JavaScript 中添加对象数组

Question

I have set of 2 data objects and they have one same element. How do I merge theme into single array object?

var itemList = [];

var categoryList = [{
      cat_id: 1,
      cat_name: 'category1'
   },
   {
      cat_id: 2,
      cat_name: 'category2'
   }
];

var productList = [{
      cat_id: 1,
      prod_code: 'a1',
      prod_name: 'product1'
   },
   {
      cat_id: 1,
      prod_code: 'a2',
      prod_name: 'product2'
   },
   {
      cat_id: 2,
      prod_code: 'b1',
      prod_name: 'product3'
   },
   {
      cat_id: 2,
      prod_code: 'b2',
      prod_name: 'product4'
   }
]

It will look like this

itemList = [{
      cat_id: 1,
      cat_name: 'category1',
      products: [{
            prod_code: 'a1',
            prod_name: 'product1'
         },
         {
            prod_code: 'a2',
            prod_name: 'product2'
         }
      ]
   },
   {
      cat_id: 2,
      cat_name: 'category2',
      products: [{
            prod_code: 'b1',
            prod_name: 'product3'
         },
         {
            prod_code: 'b2',
            prod_name: 'product4'
         }
      ]
   }
]

I tried using itemList.push and I can't seem to get it to work.

Answer 1

let merged first two objects = {...obj1, ...obj2}; Then push that item into itemList array. Maybe this can help you !!

Answer 2

You can do the trick using map and filter

 var categoryList = [{ cat_id: 1, cat_name: 'category1' }, { cat_id: 2, cat_name: 'category2' } ]; var productList = [{ cat_id: 1, prod_code: 'a1', prod_name: 'product1' }, { cat_id: 1, prod_code: 'a2', prod_name: 'product2' }, { cat_id: 2, prod_code: 'b1', prod_name: 'product3' }, { cat_id: 2, prod_code: 'b2', prod_name: 'product4' } ]; var itemList = [...categoryList]; itemList.map(item => { item.products = productList.filter( pro => pro.cat_id === item.cat_id); }); console.log(itemList);

Answer 3

You can check my solution as below, here idea is to create a deep copy(so that categoryList will still remain the same) of the categoryList and then loop through both the lists and add the result into tempList.

var tempList = categoryList.map(a => Object.assign({}, a)); // just to do deep copy 

for( var i =0; i< tempList.length; i++) {
   var temp = [];
   for( var j =0; j< productList.length; j++){
       if(tempList[i]["cat_id"] == productList[j]["cat_id"]) {
           var obj = {};
           obj["prod_code"] = productList[j]["prod_code"];
           obj["prod_name"] = productList[j]["prod_name"];
           temp.push(obj);
       }
   }
   tempList[i]["products"] = temp;
}

console.log(JSON.stringify(tempList[0]));
console.log(JSON.stringify(tempList[1]));