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How to merge two object arrays of different size by key in JavaScript
Suppose, we have an object like this −
const obj = {
"part1": [{"id": 1, "a": 50},{"id": 2, "a": 55},{"id": 4, "a": 100}],
"part2":[{"id": 1, "b": 40}, {"id": 3, "b": 45}, {"id": 4, "b": 110}]
};We are required to write a JavaScript function that takes in one such object. The function should merge part1 and part2 of the object to form an array of objects like this −
const output = [
{"id": 1, "a": 50, "b": 40},
{"id": 2, "a": 55},
{"id": 3, "b": 45},
{"id": 4, "a": 100, "b": 110}
];Example
The code for this will be −
const obj = {
"part1": [{"id": 1, "a": 50},{"id": 2, "a": 55},{"id": 4, "a": 100}],
"part2":[{"id": 1, "b": 40}, {"id": 3, "b": 45}, {"id": 4, "b": 110}]
};
const mergeObject = (obj = {}) => {
let result = [];
result = Object.keys(obj).reduce(function (hash) {
return function (r, k) {
obj[k].forEach(function (o) {
if (!hash[o.id]) {
hash[o.id] = {};
r.push(hash[o.id]);
}
Object.keys(o).forEach(function (l) {
hash[o.id][l] = o[l];
});
});
return r;
};
}(Object.create(null)), []).sort((a, b) => {
return a['id'] − b['id'];
});
return result;
};
console.log(mergeObject(obj));Output
And the output in the console will be −
[
{ id: 1, a: 50, b: 40 },
{ id: 2, a: 55 },
{ id: 3, b: 45 },
{ id: 4, a: 100, b: 110 }
]
Updated on: 20-Nov-2020
662 Views
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