Object into array conversion using JavaScript

Question

In these I need to add the array value in which pensionname are the same. Add all amount if pensionName value are the same and rechange the array into myoutput array.

My main array:

Object, Object, Object, Object, Object, Object, Object]
Object
    amount: 2000
    member: "1"
    name: "Peter Andrews"
    pensionName: "1A"
    rowId: "row_1"
Object
    amount: 2000
    member: "1"
    name: "Peter Andrews"
    pensionName: "1A"
    rowId: "row_2"
Object
    amount: 2000
    member: "1"
    name: "Peter Andrews"
    pensionName: "1A"
    rowId: "row_3"
Object
    amount: 2000
    member: "1"
    name: "Peter Andrews"
    pensionName: "1A"
    rowId: "row_4"
Object
    amount: 2000
    member: "2"
    name: "Peter Andrews"
    pensionName: "2A"
    rowId: "row_5"
Object
    amount: 2000
    member: "2"
    name: "Peter Andrews"
    pensionName: "2A"
    rowId: "row_6"
Object
    amount: 2000
    member: "2"
    name: "Peter Andrews"
    pensionName: "2A"
    rowId: "row_7"

I need the output as:

[Object, Object]
Object
    amount: 8000
    member: "1"
    name: "Peter Andrews"
    pensionName: "1A"
    rowId: "row_1"

Object
    amount: 6000
    member: "2"
    name: "Peter Andrews"
    pensionName: "2A"
    rowId: "row_2"

So I had done:

Enter code here
_.forEach(pension,function(item) {
    key = item['pensionName'];
    if (key != "0" && key !=""){
        if (typeof(groups[key]) == "undefined") {
            count++;
            str = "row_"+count;
            groups[key] = {'member' : item['member'],'name' : item['name'],'pensionName' : item['pensionName'],'amount' : item['amount'],'rowId' : str};
        }
        else {
            groups[key]['amount'] = parseFloat(groups[key]['amount']) + parseFloat(item['amount']);
        }
    }
});

It resulted in:

1A:Object, 2A: Object]
1A: Object
    amount :200
    member :1
    name : "hello"
    name2 : 1A
    id : "row_1"
2A: Object
    amount : 200
    member : 2
    name : "hello"
    name2 : "2A"
    id : "row_2"

But I can't push it into an array:

var pensionBalance = getPension();
            pensionBalance.map(function(v){
            arr.push(v);
            });

So how can I convert it into an array and push or any other method to add the array value?

An array is an object. What do you mean, you want to loose named properties? — Eihwaz
– Eihwaz, Commented Apr 1, 2016 at 19:06
array + "" should give you exactly what you want, [Object, object] — adeneo
– adeneo, Commented Apr 1, 2016 at 19:07

Nina Scholz · Accepted Answer · 2016-04-08 09:24:33Z

1

Maybe this works for you, but I am not sure, what to do with rowId property. Take all or just the first?

Basically this solution works with the thisArg, here this from Array#forEach. this is used as a temporary object with references to array items of unique persons in grouped.

In the forEach loop, first it checks if the person is already in the grouped array and therfore in this. If not, a new object is generated and to a new property with the actual pensionName to this assigned and pushed to grouped.

Now we can access this object with the key of pensionName and add the amount and push rowId to the array for it.

temporary this object:
{
    "1A": {                       // generated in first loop
        "amount": 8000,
        "member": "1",
        "name": "Peter Andrews",
        "pensionName": "1A",
        "rowId": [
            "row_1",              // added in first
            "row_2",              // ... second
            "row_3",              // third
            "row_4"               // forth
        ]
    },
    "2A": {                       // generated in fifth loop
        "amount": 6000,
        "member": "2",
        "name": "Peter Andrews",
        "pensionName": "2A",
        "rowId": [
            "row_5",              // added in fifth
            "row_6",              // ... sixth
            "row_7"               // seventh
        ]
    }
}

var object = [{ amount: 2000, member: "1", name: "Peter Andrews", pensionName: "1A", rowId: "row_1" }, { amount: 2000, member: "1", name: "Peter Andrews", pensionName: "1A", rowId: "row_2" }, { amount: 2000, member: "3", name: "Peter Andrews", pensionName: "1A", rowId: "row_3" }, { amount: 2000, member: "1", name: "Peter Andrews", pensionName: "1A", rowId: "row_4" }, { amount: 2000, member: "2", name: "Peter Andrews", pensionName: "2A", rowId: "row_5" }, { amount: 2000, member: "2", name: "Peter Andrews", pensionName: "2A", rowId: "row_6" }, { amount: 2000, member: "2", name: "Peter Andrews", pensionName: "2A", rowId: "row_7" }],
    grouped = [];

object.forEach(function (a) {
    if (!this[a.pensionName]) {
        this[a.pensionName] = { amount: 0, member: a.member, name: a.name, pensionName: a.pensionName, rowId: [] };
        grouped.push(this[a.pensionName]);
    }
    this[a.pensionName].amount += a.amount;
    this[a.pensionName].rowId.push(a.rowId);
}, {});

document.write('<pre>' + JSON.stringify(grouped, 0, 4) + '</pre>');

edited Apr 8, 2016 at 9:24

answered Apr 1, 2016 at 19:40

Nina Scholz

388k26 gold badges367 silver badges417 bronze badges

Sign up to request clarification or add additional context in comments.

8 Comments

KARTHI SRV Over a year ago

i had some modification in question. Please review

KARTHI SRV Over a year ago

It works fine, but can you please explain this functionality.

KARTHI SRV Over a year ago

Actually, this mentioned grouped data in that grouped data, key doesn't exit. then how it add the amount into that array. If this -> mention object, then how the amount had added and pushed into grouped array

KARTHI SRV Over a year ago

yes ,But when data used to push into grouped array . grouped.push(this[a.pensionName]); used to push when key doesn't exit ?

KARTHI SRV Over a year ago

Yeah, i got it, but while creating key the all data are pushed into grouped array. if already exit how the amount pushed int0 grouped array.

|

RomanPerekhrest · Accepted Answer · 2016-04-01 20:14:04Z

Consider the following approach using Array.forEach and Array.map functions:

var grouped = {}, grouped_arr;
// pension is your initial array
pension.forEach(function(v){
    var key = v["pensionName"];
    if (grouped[key]) {
        if (v["member"] === grouped[key]["member"] 
            && v["name"] === grouped[key]["name"]) {
            grouped[key]["amount"] += v["amount"];
        }
    } else {
        grouped[key] = v;
    }
});

grouped_arr = Object.keys(grouped).map(function(k, i){
    var obj = grouped[k];
    obj["rowId"] = obj["rowId"].substring(0, obj["rowId"].indexOf("_") + 1) + (i+1);
    return obj;
});

document.write('<pre>' + JSON.stringify(grouped_arr, 0, 4) + '</pre>');

The output:

[
    {
        "amount": 8000,
        "member": "1",
        "name": "Peter Andrews",
        "pensionName": "1A",
        "rowId": "row_1"
    },
    {
        "amount": 6000,
        "member": "2",
        "name": "Peter Andrews",
        "pensionName": "2A",
        "rowId": "row_2"
    }
]

Joe Withey · Accepted Answer · 2016-04-08 09:00:44Z

1

Alternative solution:

var output = [];

pension
  .forEach(function (v, i, arr) {

    var exists = output
      .reduce(function (a, c) {
        return c.pensionName === v.pensionName ? true : a;
      }, false);

    if (exists) return;

    var obj = arr
      .filter(function (p) {
        return p.pensionName === v.pensionName;
      })
      .reduce(function (a, c) {
        a.amount = a.amount + c.amount;
        return a
      });

    output.push(obj);
  });

output.map(function (v, i) {
  v.rowId = 'row_' + (i + 1);

  return v;
});

answered Apr 8, 2016 at 9:00

Joe Withey

9918 silver badges11 bronze badges

Comments

KARTHI SRV · Accepted Answer · 2016-04-08 09:26:19Z

var pension = [{ amount: 2000, member: "1", name: "Peter Andrews", pensionName: "1A", rowId: "row_1" }, { amount: 2000, member: "1", name: "Peter Andrews", pensionName: "1A", rowId: "row_2" }, { amount: 2000, member: "3", name: "Peter Andrews", pensionName: "1A", rowId: "row_3" }, { amount: 2000, member: "1", name: "Peter Andrews", pensionName: "1A", rowId: "row_4" }, { amount: 2000, member: "2", name: "Peter Andrews", pensionName: "2A", rowId: "row_5" }, { amount: 2000, member: "2", name: "Peter Andrews", pensionName: "2A", rowId: "row_6" }, { amount: 2000, member: "2", name: "Peter Andrews", pensionName: "2A", rowId: "row_7" }],
grouped = [];
var pensionData = new Array();
var count = 0;
var str;

pension.forEach(function (a) {
  if (!this[a.pensionName]) { 
    count++;
    str = "row_"+count;
    this[a.pensionName] = { amount: 0, member: a.member, name: a.name, pensionName: a.pensionName, rowId: str };
     pensionData.push(this[a.pensionName]);
  }
 this[a.pensionName].amount += a.amount;
}, {});

The output:

[
 {
    "amount": 8000,
    "member": "1",
    "name": "Peter Andrews",
    "pensionName": "1A",
    "rowId": "row_1"
 },
 {
    "amount": 6000,
    "member": "2",
    "name": "Peter Andrews",
    "pensionName": "2A",
    "rowId": "row_2"
 }
]

Collectives™ on Stack Overflow

Object into array conversion using JavaScript

4 Answers 4

8 Comments

Comments

Comments

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

4 Answers 4

8 Comments

Comments

Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Related