CODEWITHSUNDEEP
javascriptjqueryarrayssortingjavascript-objects
jonathanGB
jonathanGB

Reputation: 1540

Sort array of objects following multiple rules in javascript

So I have an array of objects, and I would like to sort them following these two rules (in order of priority):

  1. The numbers must be in numerical order
  2. The times must be in chronological order

So, I want the objects not only to be sorted by numbers, but to be also be sorted by time. For example, this would be ok.

This is the structure of the part of the objects that interests us:

var notSortedData = {
                        number: number, // it's a string
                        scheduled_date: scheduled_date, // the format is "YYYY-MM-DD HH:MM:SS"
                    }

                    sortedTrains.push(notSortedData);

So, notSortedData is pushed in sortedTrains via a for loop. Then I do this, but it is not enough (as it doesn't respect my second condition):

// sorts all the numbers numerically
        sortedTrains.sort(function(a, b) {
            return parseInt(a.number) - parseInt(b.number);
        });

What do I need to do to make sure that my second condition is also respected? Thanks!

Upvotes: 2

Views: 1559

Answers (2)

Borys Generalov
Borys Generalov

Reputation: 2345

I would suggest to utilize a library such as underscore or lo-Dash, because later you might add more sort conditions or change them and using the library will greatly reduce the noisiness of your code and save you development effort. Assuming lo-Dash is used, the code will be as elegant as follows:

var sortedTrains = [
  { 'number': 5,  'scheduled_date': '2014-10-12 00:00:00'},
  { 'number': 5,  'scheduled_date': '2014-10-12 01:00:00' },
  { 'number': 5,  'scheduled_date': '2014-10-12 02:00:00'},
  { 'number': 6,  'scheduled_date': '2014-10-12 03:00:00' }
];

var result = _.sortBy(sortedTrains, ['number', 'scheduled_date']);

Upvotes: 0

soktinpk
soktinpk

Reputation: 3888

You can try this:

sortedTrains.sort(function(a, b) {
    // We parse the numbers
    var num1 = parseInt(a.number), num2 = parseInt(b.number);
    if (num1 != num2) return num1 - num2; // Return the difference IF they are not equal
    var date1 = new Date(a.scheduled_date), date2 = new Date(b.scheduled_date);
    // We only get here if the numbers are equal
    return date1 - date2;
});

Upvotes: 2

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