Javascript get value in json based on another value

Question

I have a json similar to this one

 {      
    "id": "1",
    "month": "January",
    "type": "inc",
    "Value": "780.00",
    "year": "2018",
  },

 {      
    "id": "2",
    "month": "January",
    "type": "inc",
    "Value": "80.00",
    "year": "2018",
  },
 {      
    "id": "3",
    "month": "February",
    "type": "inc",
    "Value": "100.00",
    "year": "2018",
  },...

Now I need to get all the Value from the object for all the months, as you can see I may have more objects with the same month name. The closer I got to was creating 2 arrays 1 with the list of Months and 1 with the value but I got stuck, can someone lead me to the correct path?

The desired output would be to get an array like that ["January"=>1500, "February"=>2000...] or have 2 arrays, 1 with the list of months where there is income (I already have it) and the second the total income for these months, so it's like this: ["January", "February", "March"..] and the second one [1500, 2000, 300...]

Post the desired output and what you've tried so far. – Ele Nov 02 '18 at 14:44 — Ele, Nov 02 '18 at 14:44

Ele · Accepted Answer · 2018-11-02T14:52:34.393

5

You can use the function Array.prototype.reduce to sum each Value by month.

let arr =  [{          "id": "1",    "month": "January",    "type": "inc",    "Value": "780.00",    "year": "2018",  }, {          "id": "2",    "month": "January",    "type": "inc",    "Value": "80.00",    "year": "2018",  }, {          "id": "3",    "month": "February",    "type": "inc",    "Value": "100.00",    "year": "2018",  }],
    result = arr.reduce((a, {month, Value}) => {
      a[month] = (a[month] || 0) + +Value;
      return a;
    }, Object.create(null));
  
console.log(result);

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edited Nov 02 '18 at 14:52

answered Nov 02 '18 at 14:47

Ele

33,468
7
37
75

That's good, but I would need the total values in a month to be the sum, so January would be 860 – loliki Nov 02 '18 at 14:51
1

@Radu033 Is it not possible to loop over those values and add them up? – Cory Fail Nov 02 '18 at 14:52
wow, so simple, and nice thank you, and I had over 25 lines of code so far. – loliki Nov 02 '18 at 14:54

Ahsan Sohail · Answer 2 · 2018-11-02T14:50:04.307

1

You can do

    var fabuaryDate = yourdata
.filter(function(data) { return data.month == "February" })
.map(function(x){return {value: x.Value} })

edited Nov 02 '18 at 14:50

answered Nov 02 '18 at 14:45

Ahsan Sohail

660
6
17

yes but that will get it only for february, I need it for all months to put it in a chart – loliki Nov 02 '18 at 14:47

score 1 · Answer 3 · answered Nov 02 '18 at 14:48

1

I actually can barely understand what you would like to achieve. Please provide some example. If I understood you correctly, you can use map function of js array to map each object to its Value.

let arr = [...];
console.log(arr.map(item => item.Value));

answered Nov 02 '18 at 14:48

Uriah Ahrak

31
1

Sorry, I explained better in my question – loliki Nov 02 '18 at 14:51

score 1 · Answer 4 · answered Nov 02 '18 at 14:54

To get result in following format :

{
  jan : [1,2,3],
  feb : [3,4,5,6],
  april : [3,4,5]
}

do this :

var output = {}
arr.forEach(element => {
   if(!output[element.month]){
      output[month] = new Array();
   }
   output[month].push(element.value);
});

Niche · Answer 5 · 2018-11-02T15:01:20.653

You can iterate the object and fill an array with the values of the field you want to extract, like so:

const data = [ {      
    "id": "1",
    "month": "January",
    "type": "inc",
    "Value": 780.00,
    "year": "2018",
  },
  {      
    "id": "2",
    "month": "January",
    "type": "inc",
    "Value": 80.00,
    "year": "2018",
  },
  {      
    "id": "3",
    "month": "February",
    "type": "inc",
    "Value": 100.00,
    "year": "2018",
  }];
  
let dataArray = data.reduce((accum, d) => {
  if(!accum[d.month]) accum[d.month] = 0;
  accum[d.month] += d.Value;
  return accum;
},{});
console.log(dataArray);

score 1 · Answer 6 · answered Nov 02 '18 at 15:24

Although you don't seem to be clear enough with what have you tried here is an example of what you could do in order to read all the values inside the json.

function myFunction(item) {
   console.log(item.month + " with the value " + item.Value)
}

var jsonArray = [{"id": "1","month": "January", "type": "inc", "Value": "780.00", "year": "2018" }, { "id": "2",      "month": "January",  "type": "inc",   "Value": "80.00", "year": "2018"  }, { "id": "3", "month": "February",      "type": "inc", "Value": "100.00", "year": "2018" }];

jsonArray.forEach(myFunction);

Since you're working with an array of objects you must access to each of the objects in the array and then get the attribute that you require.

Hope this help, have a great day.

Javascript get value in json based on another value

6 Answers6