pivoting array of object data javascript

Question

so i have an array of object like this:

const data =[{
    "username": "MT220047",
    "title": "Test",
    "position": "Management Trainee",
    "department": "Logistic",
    "2022-11-15": 1,
    "2022-11-16": 2
  },
  {
    "username": "MT220047",
    "title": "UntitledForm1",
    "position": "Management Trainee",
    "department": "Logistic",
    "2022-11-16": 1
  },
  {
    "username": "17000691",
    "title": "Test",
    "position": "Foreman",
    "department": "Production",
    "2022-11-16": 1,
    
  }
]

const date =["2022-11-11","2022-11-12","2022-11-13","2022-11-14","2022-11-15","2022-11-16"]

const accumulator = {}
const final =[]
const res = date.map((tanggal)=>{ return data.reduce((a,e)=>(a[e.tanggal]={...(a[e.tanggal] || {}), ...e}, a),{});})
       
console.log(res)

it try to get the summary or pivot value of the dates, but i get this result instead of what i expected:

[ { undefined:
     { username: '17000691',
       title: 'Test',
       position: 'Foreman',
       department: 'Production',
       '2022-11-15': 1,
       '2022-11-16': 1 } },
  { undefined:
     { username: '17000691',
       title: 'Test',
       position: 'Foreman',
       department: 'Production',
       '2022-11-15': 1,
       '2022-11-16': 1 } },
  { undefined:
     { username: '17000691',
       title: 'Test',
       position: 'Foreman',
       department: 'Production',
       '2022-11-15': 1,
       '2022-11-16': 1 } },
 ....]

my expected result should be like this: i try to get the summary total of the dates base on the date array...

 summary_date:[ {"2022-11-15": 1},{"2022-11-16": 4}]

or is it possible to get this result:

data = [{"date":"2022-11-16","total":4},{"date":"2022-11-15","total":1}]

any help on this, or can someone tellme where did i do wrong here?

Can you refactor your map/reduce line with more descriptive names? Generally it’s really hard to help if we need to read very terse code. Also not sure why this is tagged as Java? — LawrenceWebDev
– LawrenceWebDev, Commented Nov 30, 2022 at 2:29
uhmm can you explains what did you mean by more descriptive.... — JS24
– JS24, Commented Nov 30, 2022 at 2:30
i try to get the summary total of the dates base on the date array... — JS24
– JS24, Commented Nov 30, 2022 at 2:31

Carsten Massmann · Accepted Answer · 2022-11-30 03:53:53Z

1

A combination of an outer .reduce() over the data array with an inner .foreach() over all the dates should do it:

const data =[{
"username": "MT220047",
"title": "Test",
"position": "Management Trainee",
"department": "Logistic",
"2022-11-15": 1,
"2022-11-16": 2
  },
  {
"username": "MT220047",
"title": "UntitledForm1",
"position": "Management Trainee",
"department": "Logistic",
"2022-11-16": 1
  },
  {
"username": "17000691",
"title": "Test",
"position": "Foreman",
"department": "Production",
"2022-11-16": 1,

  }
]

const dates =["2022-11-11","2022-11-12","2022-11-13","2022-11-14","2022-11-15","2022-11-16"]

const res=data.reduce((ac,c)=>{
 const a=(ac[c.title]??={});
 dates.forEach(d=>{if(c[d]) a[d]=(a[d]??0)+c[d]});
 return ac;
}, {});

console.log(res);

// convert res into an array of objects resa:
const resa=Object.entries(res).reduce((a,[k,v])=>
 [...a,{title:k},...Object.entries(v).map(([k,v])=>({[k]:v}))], []);
console.log(resa);

The .forEach() callback function

d=>{if(c[d]) a[d]=(a[d]??0)+c[d]}

does the following:

For each date d it checks whether the current data element c has a property d
if so, the element a[d] of the accumulator object a is checked for existence and, if necessary, initialised to 0
the value of c[d] is then added to a[d]

Yet another update to the updated question:

const data =[{
"username": "MT220047",
"title": "Test",
"position": "Management Trainee",
"department": "Logistic",
"2022-11-15": 1,
"2022-11-16": 2
  },
  {
"username": "MT220047",
"title": "UntitledForm1",
"position": "Management Trainee",
"department": "Logistic",
"2022-11-16": 1
  },
  {
"username": "17000691",
"title": "Test",
"position": "Foreman",
"department": "Production",
"2022-11-16": 1,

  }
]

const dates =["2022-11-11","2022-11-12","2022-11-13","2022-11-14","2022-11-15","2022-11-16"]

const res=Object.entries(data.reduce((a,c)=>{
 dates.forEach(d=>{if(c[d]) a[d]=(a[d]??0)+c[d]});
 return a;
}, {})).map(([date,total])=>({date,total}));

console.log(res);

Changing your question several times makes it unnecessarily hard for anyone to answer it. Please phrase any question you post here carefully and consider that others are investing their time and effort into preparing (and updating!) answers for you.

edited Nov 30, 2022 at 3:53

answered Nov 30, 2022 at 2:44

Carsten Massmann

28.4k3 gold badges25 silver badges49 bronze badges

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

8 Comments

JS24 Over a year ago

can you explained to me the function for the dates.forEach?...

JS24 Over a year ago

i just update my question @CarstenMassmann

Carsten Massmann Over a year ago

And I updated my answer. My res object looks slightly different from your expected res array. But in my view it makes more sense like that. You can, however, easily convert it to your format.

JS24 Over a year ago

is it possible to set the result into array of object?

Carsten Massmann Over a year ago

Yes: resa is now an array of objects. Exactly as specified in your question.

|

Collectives™ on Stack Overflow

pivoting array of object data javascript

1 Answer 1

Yet another update to the updated question:

8 Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

Yet another update to the updated question:

8 Comments

Your Answer

Sign up or log in

Post as a guest

Related