I have arr array of objects, I need to pivot it with product,calorie and apply (grouping & sum) on remaining parameters.
And then require data in single object. I tried below code, it works fine but I divided code in 3 parts. Could I have better code than this or it is ok.
var arr = [{
"product": "Jam",
"calorie": 2000,
"A": 300,
"B": 500,
"type": "Daily"
},
{
"product": "Sugar",
"calorie": 1000,
"A": 100,
"B": 200,
"type": "Daily"
}
]
var a1 = {}
var a2 = {}
//Step-1 Pivot
for (let i = 0; i < arr.length; i++) {
a1[arr[i]['product']] = arr[i]['calorie'];
}
//Step-2 Group and sum
a2 = groupAndSum(arr, ['type'], ['A', 'B'])[0];
//Step-3 merging.
console.log({ ...a1,
...a2
})
//General grouping and summing function that accepts an
//@Array:Array of objects
//@groupKeys: An array of keys to group by,
//@sumKeys - An array of keys to sum.
function groupAndSum(arr, groupKeys, sumKeys) {
return Object.values(
arr.reduce((acc, curr) => {
const group = groupKeys.map(k => curr[k]).join('-');
acc[group] = acc[group] || Object.fromEntries(groupKeys.map(k => [k, curr[k]]).concat(sumKeys.map(k => [k, 0])));
sumKeys.forEach(k => acc[group][k] += curr[k]);
return acc;
}, {})
);
}Here a single function which takes 3 params:
const func = (arr, pivot_vals, sum_vals) => {
return arr.reduce((a, v) => {
pivot_vals.forEach((pivot) => {
a[v[pivot[0]]] = v[pivot[1]];
});
sum_vals.forEach((key) => {
if (!a[key]) a[key] = 0;
a[key] += v[key];
});
return a;
},{});
};
arr
containing the data
sum_vals
array with all props you want do be summed
pivot_vals
nested array with the props which should be linked
I wans't sure what to do with the type, since it is a string it can`t be summed. Did you want to count the amount of types ?
let arr = [
{
product: "Jam",
calorie: 2000,
A: 300,
B: 500,
type: "Daily",
},
{
product: "Sugar",
calorie: 1000,
A: 100,
B: 200,
type: "Daily",
},
];
let sum_vals = ["A","B"]
let pivot_vals = [["product", "calorie"]];
const func = (arr, pivot_vals, sum_vals) => {
return arr.reduce((a, v) => {
pivot_vals.forEach((pivot) => {
a[v[pivot[0]]] = v[pivot[1]];
});
sum_vals.forEach((key) => {
if (!a[key]) a[key] = 0;
a[key] += v[key];
});
return a;
},{});
};
console.log(func(arr, pivot_vals, sum_vals));