I have data in this format
const ChkdArr = [
{
date: "2022-05-25",
itemId: 29,
quantity: 4,
},
{
date: "2022-05-26",
itemId: 29,
quantity: 2,
},
{
date: "2022-05-25",
itemId: 36,
quantity: 7,
},
{
date: "2022-05-25",
itemId: 36,
quantity: 4,
},
{
date: "2022-05-27",
itemId: 36,
quantity: 2,
},
{
date: "2022-05-28",
itemId: 47,
quantity: 1,
},
];
i am getting trouble to get a new array with those data whose itemid is same and in those item if the date is same sum up their quantity.
I want the result to look like this i am applying map and filters but my data is repeating and having incorrect results
const DateSortArr = [{
itemId: 29,
date: [
{ date: "2022-05-25", quantity: 4 },
{ date: "2022-05-26", quantity: 2 },
],
},
{
itemId: 36,
date: [
{ date: "2022-05-25", quantity: 11 },
{ date: "2022-05-27", quantity: 2 },
],},
{
itemId: 47,
date: [{ date: "2022-05-25", quantity: 1 }],
},
];
Hello I don't know id undrestand you but you use this fun :
function groupBy(collection, property) {
var i = 0, val, index,
values = [], result = [];
for (; i < collection.length; i++) {
val = collection[i][property];
index = values.indexOf(val);
if (index > -1)
result[index].push(collection[i]);
else {
values.push(val);
result.push([collection[i]]);
}
}
return result;
}
const ChkdArr = [
{
date: "2022-05-25",
itemId: 29,
quantity: 4,
},
{
date: "2022-05-26",
itemId: 29,
quantity: 2,
},
{
date: "2022-05-25",
itemId: 36,
quantity: 7,
},
{
date: "2022-05-25",
itemId: 36,
quantity: 4,
},
{
date: "2022-05-27",
itemId: 36,
quantity: 2,
},
{
date: "2022-05-28",
itemId: 47,
quantity: 1,
},
];
var obj = groupBy(ChkdArr, "date");
console.log(obj)
const ChkdArr = [
{
date: "2022-05-25",
itemId: 29,
quantity: 4,
},
{
date: "2022-05-26",
itemId: 29,
quantity: 2,
},
{
date: "2022-05-25",
itemId: 36,
quantity: 7,
},
{
date: "2022-05-25",
itemId: 36,
quantity: 4,
},
{
date: "2022-05-27",
itemId: 36,
quantity: 2,
},
{
date: "2022-05-28",
itemId: 47,
quantity: 1,
},
];
let answer = [];
ChkdArr.map(item =>{
let id = answer.findIndex(it =>it.itemId === item.itemId);
if(id === - 1 ){
answer.push({itemId: item.itemId, data: [{date: item.date, quantity: item.quantity}]})
}else{
answer [id] = {itemId: item.itemId, data: [...answer[id].data, {date: item.date, quantity: item.quantity}]}
}
})
console.log(answer)
This can be done efficiently using a map, and a new output array. In the map, we will store the key as itemId and value as its index in the output array. Then we will loop through the data, and see if the itemId has an index in the map, if it is we will look up that item value from output array, and update the current date value accordingly, otherwise we will create a new object for that item in the array. The below code does just that.
const data = [
{
date: "2022-05-25",
itemId: 29,
quantity: 4,
},
{
date: "2022-05-26",
itemId: 29,
quantity: 2,
},
{
date: "2022-05-25",
itemId: 36,
quantity: 7,
},
{
date: "2022-05-25",
itemId: 36,
quantity: 4,
},
{
date: "2022-05-27",
itemId: 36,
quantity: 2,
},
{
date: "2022-05-28",
itemId: 47,
quantity: 1,
},
];
let output = [];
let itemIdToIndexMap = {};
data.forEach(item => {
const itemIndex = itemIdToIndexMap[item.itemId];
if(itemIndex !== undefined) {
const itemArray = output[itemIndex];
const itemWithCurrentDate = itemArray.date.find(newItem => item.date === newItem.date);
if(itemWithCurrentDate) {
itemWithCurrentDate.quantity += item.quantity;
} else {
itemArray.date.push({date: item.date, quantity: item.quantity});
}
} else {
output.push({itemId: item.itemId, date: [{date: item.date, quantity: item.quantity}]});
itemIdToIndexMap[item.itemId] = output.length - 1;
}
});
console.log(JSON.stringify(output));