0
197
ViewsHow to add a new entry to an array after a certain property changes?
I am trying to add a new entry to an array after a certain property, in my case " place", changes. However, I have big problems to find a suitable approach, because the operation depends on the next object in the array.
const initalData = [
{ storyID: 1, place: 12, type: "Story" },
{ storyID: 5, place: 12, type: "Story" },
{ storyID: 99, place: 45, type: "Story" },
{ storyID: 8, place: 31, type: "Story" },
{ storyID: 16, place: 31, type: "Story" },
{ storyID: 20, place: 45, type: "Story" },
{ storyID: 22, place: 45, type: "Story" },
];
const targetData = [
{ placeID: 12, type: "Place" }, // new added entry based on the next "place"
{ storyID: 1, place: 12, type: "Story" },
{ storyID: 5, place: 12, type: "Story" },
{ placeID: 45, type: "Place" }, // // new added entry based on the next "place"
{ storyID: 99, place: 45, type: "Story" },
{ placeID: 31, type: "Place" }, // new added entry based on the next "place"
{ storyID: 8, place: 31, type: "Story" },
{ storyID: 16, place: 31, type: "Story" },
{ placeID: 45, type: "Place" },// new added entry based on the next "place"
{ storyID: 20, place: 45, type: "Story" },
{ storyID: 22, place: 45, type: "Story" },
];
Currently I have looked at groupBy("place") as a possible approach, but the ultimate array structure here is not what I need.
·
Juan Pablo Isaza
1 answers
Answer question0
Here is the implementation
const initalData = [
{ storyID: 1, place: 12, type: "Story" },
{ storyID: 5, place: 12, type: "Story" },
{ storyID: 99, place: 45, type: "Story" },
{ storyID: 8, place: 31, type: "Story" },
{ storyID: 16, place: 31, type: "Story" },
{ storyID: 20, place: 45, type: "Story" },
{ storyID: 22, place: 45, type: "Story" },
];
let oldPlace = null;
let resultData = [];
for (let row of initalData) {
if (row.place != oldPlace) {
resultData.push({ placeID: row.place, type: "Place" });
oldPlace = row.place;
}
resultData.push(row);
}
console.log (resultData);
·
Juan Pablo Isaza
Report
Answer question