How do I group array by name but taking minimum of all start dates and max of all end dates using Javascript

Question

Below is the array that has 2 elements with Plan as name.I want to group the array using Javascript by name but the StartDate should be the minimum of all startdates that has name as Plan and EndDate should be max of all enddates that has name as plan.I want to group the elements and not sort them.

[{"Name":"Define","StartDate":"2015-04-09","EndDate":"2015-04-22"},
{"Name":"Plan","StartDate":"2015-04-22","EndDate":"2015-04-29"},
{"Name":"Plan","StartDate":"2015-04-30","EndDate":"2015-05-14"]}]

So my final array should be like below

 [{"Name":"Define","StartDate":"2015-04-09","EndDate":"2015-04-22"},
    {"Name":"Plan","StartDate":"2015-04-22","EndDate":"2015-05-14"]}]

I have got stucked in building the logic.Help appreciated.

Check the conditions before push the item. Please, put your JavaScript code — oscarvady, Apr 16 '15 at 13:55
check this out, fits exactly you'r question http://stackoverflow.com/questions/22954066/group-by-and-aggregation-on-json-array-using-underscore-js — Danny, Apr 16 '15 at 13:56
possible duplicate of [Sort Javascript Object Array By Date](http://stackoverflow.com/questions/10123953/sort-javascript-object-array-by-date) — kemicofa ghost, Apr 16 '15 at 13:58
@oscarvady Thanks! but i have no code yet except the array.Good if you can help. — Viral, Apr 16 '15 at 14:33
@Danny But its using underscore.js.I would want to do it in simple js or jquery, — Viral, Apr 16 '15 at 14:34
@Viral did you check the possible duplicate link by Grimbode ? That looks like it. — Praveen Puglia, Apr 16 '15 at 14:39

score 0 · Accepted Answer · answered Apr 16 '15 at 14:05

0

Here's how you can do it using underscore.js (http://underscorejs.org/)

arr = [{"Name":"Define","StartDate":"2015-04-09","EndDate":"2015-04-22"},
{"Name":"Plan","StartDate":"2015-04-22","EndDate":"2015-04-29"},
{"Name":"Plan","StartDate":"2015-04-30","EndDate":"2015-05-14"}];

result = _.chain(arr)
 .groupBy(function(e){ return e.Name })
 .pairs()
 .map(function(e){  
  return {
   Name: e[0],
   StartDate: _.chain(e[1]).sortBy(function(e){ return new Date(e.StartDate).getTime(); }).first().value().StartDate,
   EndDate: _.chain(e[1]).sortBy(function(e){ return -1 * new Date(e.EndDate).getTime(); }).first().value().EndDate
  }
 })
 .value()

answered Apr 16 '15 at 14:05

Furqan Zafar

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Can you help me doing this with simple js or jquery. – Viral Apr 16 '15 at 14:25
Thanks a lot.I have now used underscore.can you help if my array contains one more element eg Id ,how do I get that? – Viral Apr 16 '15 at 15:42
Eg : [{"Id":"1","Name":"Define","StartDate":"2015-04-09","EndDate":"2015-04-22"}, {"Id":"2","Name":"Plan","StartDate":"2015-04-22","EndDate":"2015-04-29"}, {"Id":"2","Name":"Plan","StartDate":"2015-04-30","EndDate":"2015-05-14"]}] – Viral Apr 16 '15 at 15:43
Furqan , What changes shall I make in the code to get some additional parameter from array.My new array looks like one above. – Viral Apr 17 '15 at 05:00
Just add Id: _.first(e[1]).Id to the object returned by the last map function. – Furqan Zafar Apr 17 '15 at 07:51

How do I group array by name but taking minimum of all start dates and max of all end dates using Javascript

1 Answers1