so i have a question how to turn this object :
let data = [
{"branch": "london", "date": "2020-05-07", "sales": 500},
{"branch": "london", "date": "2020-05-08", "sales": 1500},
{"branch": "london", "date": "2020-05-09", "sales": 1000},
{"branch": "london", "date": "2020-06-09", "sales": 1000},
{"branch": "wales", "date": "2020-05-10", "sales": 2000},
{"branch": "wales", "date": "2020-05-11", "sales": 3000},
{"branch": "wales", "date": "2020-06-12", "sales": 2500},
{"branch": "wales", "date": "2020-08-12", "sales": 1500}
]
into that object :
let monthlyData = [
{"branch": "london", "date": "2020-05", "sales": 3000},
{"branch": "london", "date": "2020-06", "sales": 1000},
{"branch": "wales", "date": "2020-05", "sales": 5000},
{"branch": "wales", "date": "2020-06", "sales": 2500},
{"branch": "wales", "date": "2020-08", "sales": 1500},
]
so my goal here is to have every branch give me a monthly record instead of daily how to solve this as I have only managed to do it but with the date and sales expanding the current object instead of creating a new one with the new month data.
You could do it with Array.prototype.reduce():
const data = [
{"branch": "london", "date": "2020-05-07", "sales": 500},
{"branch": "london", "date": "2020-05-08", "sales": 1500},
{"branch": "london", "date": "2020-05-09", "sales": 1000},
{"branch": "london", "date": "2020-06-09", "sales": 1000},
{"branch": "wales", "date": "2020-05-10", "sales": 2000},
{"branch": "wales", "date": "2020-05-11", "sales": 3000},
{"branch": "wales", "date": "2020-06-12", "sales": 2500},
{"branch": "wales", "date": "2020-08-12", "sales": 1500}
];
const monthlyData=Object.values(data.reduce((a,c)=>{
const bd=c.branch+c.date.substr(0,7); // generate a unique key for branch and month
if (!a[bd]) a[bd]={...c,date:c.date.substr(0,7)}; // create an entry for bd
else a[bd].sales+=c.sales; // add sales to existing bd entry
return a; // Object.values: create an array by
},{})); // extracting all values from the object
console.log(monthlyData)Updated:
At first I didn't spot the branch property. This has now been fixed.
i solved the issue by using 2 for each loops
let data = [
{"branch": "london", "date": "2020-05-07", "sales": 500},
{"branch": "london", "date": "2020-05-08", "sales": 1500},
{"branch": "london", "date": "2020-05-09", "sales": 1000},
{"branch": "london", "date": "2020-06-09", "sales": 1000},
{"branch": "wales", "date": "2020-05-10", "sales": 2000},
{"branch": "wales", "date": "2020-05-11", "sales": 3000},
{"branch": "wales", "date": "2020-05-12", "sales": 2100},
{"branch": "wales", "date": "2020-06-12", "sales": 2500},
{"branch": "wales", "date": "2020-08-12", "sales": 1500},
{"branch": "wales", "date": "2020-09-12", "sales": 200},
]
monthlyData = []
data.forEach((dataSet) => {
if (monthlyData.length === 0) {
newObj = {
"branch": dataSet.branch,
"date": dataSet.date.substring(0,7),
"sales": dataSet.sales
}
monthlyData.push(newObj)
} else {
let found = false
monthlyData.forEach((month) => {
if (month.branch === dataSet.branch && month.date === dataSet.date.substring(0,7)) {
month.sales += dataSet.sales
found = true
}
})
if (!found) {
newObj = {
"branch": dataSet.branch,
"date": dataSet.date.substring(0,7),
"sales": dataSet.sales
}
monthlyData.push(newObj)
}
}
})