Javascript merging duplicates in an array of objects-CodePudding

I have an array of objects like this-

    {"zone":"lobby a","time":"00:00","hub":"I","Sum":0.0,"schedule":"2022"},
    {"zone":"lobby b","time":"00:01","hub":"I","Sum":1.0,"schedule":"112022"},
    {"zone":"lobby a","time":"00:01","hub":"I","Sum":2.0,"schedule":"11_2022"},
    {"zone":"lobby b","time":"00:03","hub":"I","Sum":0.0,"schedule":"11_2022"},
    {"zone":"lobby c","time":"00:04","hub":"I","Sum":1.0,"schedule":"11_2022"},
    {"zone":"lobby c","time":"00:04","hub":"I","Sum":2.0,"schedule":"11_2022"},

The duplicate 'time' need to be merged by adding the Sums only if the zone is same.

Result should be

    {"zone":"lobby a","time":"00:00","hub":"I","Sum":0.0,"schedule":"2022"},
    {"zone":"lobby b","time":"00:01","hub":"I","Sum":1.0,"schedule":"112022"},
    {"zone":"lobby a","time":"00:01","hub":"I","Sum":2.0,"schedule":"11_2022"},
    {"zone":"lobby b","time":"00:03","hub":"I","Sum":0.0,"schedule":"11_2022"},
    {"zone":"lobby c","time":"00:04","hub":"I","Sum":3.0,"schedule":"11_2022"},

Any help will be much appreciated. I ahve tried many options using maps etc. but not succesfull.

CodePudding user response：

The following function uses a grouping function to associate items with one another, and a merging function to perform the addition of the sums.

For each item in the data, the group is determined and the group is replaced by the result of the existing group merged with the current item in that group.

Time complexity is O(n) (one iteration to group the items, one iteration to enumerate the resulting grouped items).

const data = [
    {"zone":"lobby a","time":"00:00","hub":"I","Sum":0.0,"schedule":"2022"},
    {"zone":"lobby b","time":"00:01","hub":"I","Sum":1.0,"schedule":"112022"},
    {"zone":"lobby a","time":"00:01","hub":"I","Sum":2.0,"schedule":"11_2022"},
    {"zone":"lobby b","time":"00:03","hub":"I","Sum":0.0,"schedule":"11_2022"},
    {"zone":"lobby c","time":"00:04","hub":"I","Sum":1.0,"schedule":"11_2022"},
    {"zone":"lobby c","time":"00:04","hub":"I","Sum":2.0,"schedule":"11_2022"} ]

function groupAndMerge(data, groupFn, mergeFn) {
    const result = {}
    for(let d of data) {
        result[groupFn(d)] = mergeFn(d, result[groupFn(d)] || { Sum: 0 }) 
    }
    return Object.values(result)
}

const groupFn = ({zone, time}) => zone   time
const mergeFn = (a, b) => ({ ...a, Sum: a.Sum   b.Sum })
console.log(groupAndMerge(data, groupFn, mergeFn))

CodePudding user response：

let input = [
{"zone":"lobby a","time":"00:00","hub":"I","Sum":0.0,"schedule":"2022"},
    {"zone":"lobby b","time":"00:01","hub":"I","Sum":1.0,"schedule":"112022"},
    {"zone":"lobby a","time":"00:01","hub":"I","Sum":2.0,"schedule":"11_2022"},
    {"zone":"lobby b","time":"00:03","hub":"I","Sum":0.0,"schedule":"11_2022"},
    {"zone":"lobby c","time":"00:04","hub":"I","Sum":1.0,"schedule":"11_2022"},
    {"zone":"lobby c","time":"00:04","hub":"I","Sum":2.0,"schedule":"11_2022"},
    ]

    let cleared = [];

    input.map((item, index)=>{
    const dupl_index = cleared.findIndex(itm_ =>itm_.zone === item.zone && itm_.time === item.time);
    if(dupl_index === -1){
    cleared.push(item)
    }else{
    cleared[dupl_index].Sum = Number(cleared[dupl_index].Sum   item.Sum).toFixed(1)
    }
    })

    console.log(cleared)

CodePudding user response：

const a = [
  {"zone":"lobby a","time":"00:00","hub":"I","Sum":0.0,"schedule":"2022"},
  {"zone":"lobby b","time":"00:01","hub":"I","Sum":1.0,"schedule":"112022"},
  {"zone":"lobby a","time":"00:01","hub":"I","Sum":2.0,"schedule":"11_2022"},
  {"zone":"lobby b","time":"00:03","hub":"I","Sum":0.0,"schedule":"11_2022"},
  {"zone":"lobby c","time":"00:04","hub":"I","Sum":1.0,"schedule":"11_2022"},
  {"zone":"lobby c","time":"00:04","hub":"I","Sum":2.0,"schedule":"11_2022"}
];

let r = [];
a.forEach(i => {
  let dup = r.find(j => j.zone===i.zone && j.time===i.time);
  if(dup) dup.Sum = (dup.Sum   i.Sum).toFixed(1);
  else r.push(i);
});
console.log(r);