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Grouping array nested value while comparing 2 objects - JavaScript
Suppose, we have the following JSON object −
const input = {
"before": {
"device": [
{
"id": "1234",
"price": "10",
"features": [
{
"name": "samsung",
"price": "10"
},
{
"name": "Apple",
"price": "20"
}
]
},
{
"id": "2154",
"price": "20",
"features": [
{
"name": "samsung",
"price": "30"
},
{
"name": "Moto",
"price": "40"
}
]
}
]
},
"after": {
"device": [
{
"id": "1234",
"price": "50",
"features": [
{
"name": "samsung",
"price": "20"
},
{
"name": "Lenovo",
"price": "30"
}
]
},
{
"id": "2158",
"price": "40",
"features": [
{
"name": "samsung",
"price": "30"
}
]
}
]
}
};Our requirement is to group the id & its feature into a single row if the same id is there in the before & after object.
And the required output can be better described by the following visual representation.
We are required to write a function that groups and sorts the data in the same way.
Example
Following is the code −
const input = {
"before": {
"device": [
{
"id": "1234",
"price": "10",
"features": [
{
"name": "samsung",
"price": "10"
},
{
"name": "Apple",
"price": "20"
}
]
},
{
"id": "2154",
"price": "20",
"features": [
{
"name": "samsung",
"price": "30"
},
{
"name": "Moto",
"price": "40"
}
]
}
]
},
"after": {
"device": [
{
"id": "1234",
"price": "50",
"features": [
{
"name": "samsung",
"price": "20"
},
{
"name": "Lenovo",
"price": "30"
}
]
},
{
"id": "2158",
"price": "40",
"features": [
{
"name": "samsung",
"price": "30"
}
]
}
]
}
};
const formatJSON = data => {
const sub = Object.fromEntries(Object.keys(data).map(k => [k, 0]));
return Object.values(Object.entries(data).reduce((r, [col, { device }])
=> {
device.forEach(({ id, price, features }) => {
r[id] = r[id] || [{ id, ...sub }];
r[id][0][col] = price;
features.forEach(({ name, price }) => {
let temp = r[id].find(q => q.name === name);
if (!temp){
r[id].push(temp = { name, ...sub });
};
temp[col] = price;
});
});
return r;
}, {}));
};
console.log(formatJSON(input));Output
This will produce the following output on console −
[
[
{ id: '1234', before: '10', after: '50' },
{ name: 'samsung', before: '10', after: '20' },
{ name: 'Apple', before: '20', after: 0 },
{ name: 'Lenovo', before: 0, after: '30' }
],
[
{ id: '2154', before: '20', after: 0 },
{ name: 'samsung', before: '30', after: 0 },
{ name: 'Moto', before: '40', after: 0 }
],
[
{ id: '2158', before: 0, after: '40' },
{ name: 'samsung', before: 0, after: '30' }
]
]
Updated on: 01-Oct-2020
314 Views
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