I am trying to study Array.reduce
. And I was given the following task:
Input data:
const report = [
{
dateOfReport: "11-01-2021",
userId: "id1",
userMetric: { first_metric: 10, second_metric: 15 },
},
{
dateOfReport: "11-01-2021",
userId: "id2",
userMetric: { first_metric: 9, second_metric: 14 },
},
{
dateOfReport: "12-01-2021",
userId: "id1",
userMetric: { first_metric: 11, second_metric: 14 },
},
{
dateOfReport: "12-01-2021",
userId: "id2",
userMetric: { first_metric: 16, second_metric: 19 },
},
];
And I need to get this data in the output
const output = [
{
dateOfReport: "11-01-2021",
id1: { first_metric: 10, second_metric: 15 },
id2: { first_metric: 9, second_metric: 14 },
},
{
dateOfReport: "12-01-2021",
id1: { first_metric: 11, second_metric: 14 },
id2: { first_metric: 16, second_metric: 19 },
},
];
I tried to write some code, but I have no idea how to do it correctly. How can I solve this problem?
Code:
const result = report.reduce((acc, dataItem) => {
let outputArray = [];
if (dataItem) {
outputArray.push({ ...dataItem, date: dataItem.dateOfReport, [dataItem.userId]: dataItem.userMetric });
}
return outputArray;
});
return result;
CodePudding user response:
Corrected the logic
const report = [
{
dateOfReport: "11-01-2021",
userId: "id1",
userMetric: { first_metric: 10, second_metric: 15 },
},
{
dateOfReport: "11-01-2021",
userId: "id2",
userMetric: { first_metric: 9, second_metric: 14 },
},
{
dateOfReport: "12-01-2021",
userId: "id1",
userMetric: { first_metric: 11, second_metric: 14 },
},
{
dateOfReport: "12-01-2021",
userId: "id2",
userMetric: { first_metric: 16, second_metric: 19 },
},
];
const result = report.reduce((acc, dataItem) => {
const node = acc.find(item => item.dateOfReport === dataItem.dateOfReport);
if (node) {
node[dataItem.userId] = dataItem.userMetric;
} else {
acc.push({ dateOfReport: dataItem.dateOfReport, [dataItem.userId]: dataItem.userMetric });
}
return acc;
}, []);
console.log(result);
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