How to sort date array in javascript

Question

I have below array of dates and I want to sort it in acceding order. I tried but not getting the positive result.

var arr = [ [ '02/13/2015', 0.096 ],
  [ '11/15/2013', 0.189 ],
  [ '05/15/2014', 0.11 ],
  [ '12/13/2013', 0.1285 ],
  [ '01/15/2013', 0.12 ],
  [ '01/15/2014', 0.11 ],
  [ '02/14/2014', 0.11 ],
  [ '03/14/2014', 0.11 ],
  [ '01/15/2015', 0.096 ],
  [ '07/15/2015', 0.096 ],
  [ '04/15/2013', 0.12 ],
  [ '04/15/2014', 0.11 ],
  [ '05/15/2013', 0.12 ],
  [ '06/14/2013', 0.12 ],
  [ '06/16/2014', 0.11 ],
  [ '07/15/2013', 0.12 ],
  [ '07/15/2014', 0.11 ],
  [ '03/16/2015', 0.096 ]]

My Code

arr.sort(function(a,b){
  return new Date(a[0][0]) - new Date(b[0][0]);
});

For starters, a is an array like [ '11/15/2013', 0.189 ] so a[0][0] would result in '1'.. This still requires work, however because new Date(a[0]) - eg new Date('11/15/2013') - is ill-defined behavior. I recommend Moment.js to deal with this situation, but one can manually parse the date and use new Date(y, m, d) as well: there are no shortages of such examples when asking how to turn a string into a Date — user2864740
– user2864740, Commented Aug 14, 2015 at 7:46
For how to "properly" create a Date, see stackoverflow.com/questions/5619202/… , stackoverflow.com/questions/22184747/… , etc — user2864740
– user2864740, Commented Aug 14, 2015 at 7:51

thefourtheye · Accepted Answer · 2015-08-14 07:11:30Z

8

You are taking the first character in the date strings, converting them to Date instances and using them for comparison.

But, you should actually use the Date strings as they are, convert them to Date instances and compare them.

arr.sort(function (a, b) {
  return new Date(a[0]) - new Date(b[0]);
});

Output

[ [ '01/15/2013', 0.12 ],
  [ '04/15/2013', 0.12 ],
  [ '05/15/2013', 0.12 ],
  [ '06/14/2013', 0.12 ],
  [ '07/15/2013', 0.12 ],
  [ '11/15/2013', 0.189 ],
  [ '12/13/2013', 0.1285 ],
  [ '01/15/2014', 0.11 ],
  [ '02/14/2014', 0.11 ],
  [ '03/14/2014', 0.11 ],
  [ '04/15/2014', 0.11 ],
  [ '05/15/2014', 0.11 ],
  [ '06/16/2014', 0.11 ],
  [ '07/15/2014', 0.11 ],
  [ '01/15/2015', 0.096 ],
  [ '02/13/2015', 0.096 ],
  [ '03/16/2015', 0.096 ],
  [ '07/15/2015', 0.096 ] ]

answered Aug 14, 2015 at 7:11

thefourtheye

241k53 gold badges466 silver badges505 bronze badges

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

1 Comment

user2864740 Over a year ago

FWIW, see my comment on the main post. Passing in a locale-specific string to the Date constructor ill-defined behavior.

Nina Scholz · Accepted Answer · 2015-08-14 08:53:00Z

1

Heavily inspired from MDN Sorting with map. It is important for larger data sets.

var arr = [
    ['02/13/2015', 0.096],
    ['11/15/2013', 0.189],
    ['05/15/2014', 0.11],
    ['12/13/2013', 0.1285],
    ['01/15/2013', 0.12],
    ['01/15/2014', 0.11],
    ['02/14/2014', 0.11],
    ['03/14/2014', 0.11],
    ['01/15/2015', 0.096],
    ['07/15/2015', 0.096],
    ['04/15/2013', 0.12],
    ['04/15/2014', 0.11],
    ['05/15/2013', 0.12],
    ['06/14/2013', 0.12],
    ['06/16/2014', 0.11],
    ['07/15/2013', 0.12],
    ['07/15/2014', 0.11],
    ['03/16/2015', 0.096]
];

// temporary array holds objects with position and sort-value
var mapped = arr.map(function (el, i) {
    var d = el[0].split('/');
    return { index: i, value: new Date(d[2], d[0] - 1, d[1]) };
})

// sorting the mapped array containing the reduced values
mapped.sort(function (a, b) {
    return +(a.value > b.value) || +(a.value === b.value) - 1;
});

// container for the resulting order
var result = mapped.map(function (el) {
    return arr[el.index];
});

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

edited Aug 14, 2015 at 8:53

answered Aug 14, 2015 at 7:52

Nina Scholz

388k26 gold badges367 silver badges417 bronze badges

1 Comment

user2864740 Over a year ago

For historical purposes the month should be 0..11

Dedy Chaidir · Accepted Answer · 2015-08-14 07:22:58Z

0

If what you want is sorting only by the dates, I think this code would help:

arr.sort(function(a,b){return new Date(a[0]) - new Date(b[0]);});

answered Aug 14, 2015 at 7:22

Dedy Chaidir

97710 silver badges18 bronze badges

Collectives™ on Stack Overflow

How to sort date array in javascript

3 Answers 3

1 Comment

1 Comment

Comments

Your Answer

Linked

Hot Network Questions

Collectives™ on Stack Overflow

3 Answers 3

1 Comment

1 Comment

Comments

Your Answer

Sign up or log in

Post as a guest

Linked

Related