Is there a way to merge two nested array based on common key

sevack 0
Viewed 36

This are the two array that needs merging based on common id, the nested array should also be merged

First Array

const arr1 = [
    { id: 1, name: "sai", accounts: ["a"] },
    { id: 2, name: "King", accounts:[] },
    { id: 3, name: "Queen", accounts:["c"] },
    { id: 4, name: "kai", accounts:["e"] },
  ];

Second Array

const arr2 = [
    { id: 1, age: 23, accounts: ["b"] },
    { id: 2, age: 24, accounts:[] },
    { id: 3, age: 25, accounts:["d"] }
  ];

Output should be

[  
  { id: 1, age: 23, name:"sai", accounts: ["a","b"] },
  { id: 2, age: 24, name: "King", accounts:[] },
  { id: 3, age: 25, name:"Queen", accounts:["c","d"] },
  { id: 4, name: "kai", accounts:["e"] },
]
array-merge arrays javascript
1 Answers

This should work:

const arr1 = [
    { id: 1, name: "sai", accounts: ["a"] },
    { id: 2, name: "King", accounts:[] },
    { id: 3, name: "Queen", accounts:["c"] },
    { id: 4, name: "kai", accounts:["e"] },
];

const arr2 = [
    { id: 1, age: 23, accounts: ["b"] },
    { id: 2, age: 24, accounts:[] },
    { id: 3, age: 25, accounts:["d"] }
];

const result = arr1.map((item, i) => Object.assign({}, item, arr2[i]));

New version:

const mergeArrays = () => {
   let res = [];
   
   for (var i = 0; i < arr1.length; i++) {
       let item = arr1[i];
       
       if (arr2[i] && arr1[i].id == arr2[i].id) {
            item.age = arr2[i].age;
            item.accounts = item.accounts.concat(arr2[i].accounts);
       }
       
       res.push(item);
   }
   
   return res;
};
Mariusz Malek0
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