Grouped sorting on a JS array

Question

I have an array of objects with two properties: Name and Hours.

For example:

array = [
    {name: "ANDY", hours: 40 }, 
    {name: "ANDY", hours: 50 }, 
    {name: "GREG", hours: 40 },
]

For example in my array I would like the result of the sorting to have the Andy with the most hours first, then Andy with slightly less hours, and then Greg because his name comes later alphabetically and so on and so on.

Since the array.sort() function passes two elements of the array to compare i realise this is not the way to go for me but fail to come up with an elegant solution. Please help me out.

possible duplicate of How to sort an array of objects with multiple field values in JavaScript — Felix Kling
– Felix Kling, Commented Apr 23, 2013 at 8:26
@FelixKling: yes, asked 1000 times already, unfortunately most answers so far are lame. — georg
– georg, Commented Apr 23, 2013 at 8:28

georg · Accepted Answer · 2017-10-06 11:00:05Z

14

array = [
    {name: "ANDY", hours: 40 }, 
    {name: "GREG", hours: 40 },
    {name: "ANDY", hours: 50 }, 
]

function cmp(x, y) {
  return x > y ? 1 : (x < y ? -1 : 0);
}


array.sort(function(a, b) {
  return cmp(a.name, b.name) || cmp(b.hours, a.hours)
})

console.log(array)

If javascript had a spaceship operator that would be even more elegant. Note that this code is easy to extend to use more properties:

ary.sort(function(a, b) {
    return cmp(a.name, b.name) || cmp(a.age, b.age) || cmp(b.hours, a.hours) || ....
})

edited Oct 6, 2017 at 11:00

answered Apr 23, 2013 at 8:11

georg

216k57 gold badges324 silver badges401 bronze badges

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

2 Comments

Joseph Webber Over a year ago

You're missing semicolons on sort's return statement and the sort functions.

timoxley Over a year ago

semicolons are optional

Diode · Accepted Answer · 2013-04-24 07:34:59Z

3

var arr = [{
    name: "GREG",
    hours: "40"
}, {
    name: "ANDY",
    hours: "50"
}, {
    name: "ANDY",
    hours: "40"
}];

Array.prototype.sortOn = function(conds){
    this.sort(function(a, b){
        for(var i=0; i < conds.length; i++){
            var c = conds[i].split(" ");
            if(a[c[0]] < b[c[0]]){
                return c[1] == "asc" ? -1:1;
            }
            if(a[c[0]] > b[c[0]]){
                return c[1] == "asc" ? 1:-1;
            }
        }
        return 0;
    });
    return this;
}

arr.sortOn(["name asc", "hours dsc"]);

edited Apr 24, 2013 at 7:34

answered Apr 23, 2013 at 8:14

Diode

25.2k8 gold badges43 silver badges52 bronze badges

3 Comments

georg Over a year ago

Sorry, but this is wrong. You cannot return x > y from a sorting function.

georg Over a year ago

Nope, this is the same mistake. You should return -1, 1, or 0, not just 1, -1.

Diode Over a year ago

@thg435. Tried to find a lazy solution. Have corrected considering all conditions. Thanks :)

UltraInstinct · Accepted Answer · 2013-04-23 08:13:44Z

2

obj.sort(function(item1,item2) {
  if ( item1.Name < item2.Name )
    return -1;
  if ( item1.Name > item2.Name )
    return 1;
  return item1.Hours - item2.Hours;
});

answered Apr 23, 2013 at 8:13

UltraInstinct

44.6k12 gold badges85 silver badges108 bronze badges

Comments

Cattode · Accepted Answer · 2013-04-23 08:21:50Z

2

You can sort by Name, then sort elements who have the same name by Hours

Example:

var array = [{"Name":"ANDY", "Hours":40},
             {"Name":"ANDY", "Hours":50},
             {"Name":"GREG", "Hours":40}];


var sortedArray = array.sort(function(a,b) {
            return (a["Name"] > b["Name"]) ? 1 : -1;
    }).sort(function(a,b) {
            if(a["Name"] == b["Name"])
                return (a["Hours"] < b["Hours"]) ? 1 : -1;
            else 
                return 0;
    });

edited Apr 23, 2013 at 8:21

answered Apr 23, 2013 at 8:12

Cattode

8665 silver badges11 bronze badges

3 Comments

georg Over a year ago

Javascript sort is not guaranteed to be stable, results may vary across implementations.

Evan Trimboli Over a year ago

Why are you doing property access via brackets as opposed to dot notation?

Cattode Over a year ago

Yeah, both notations work for this particular question. Don't know exactly why I preferred using brackets. I guess it's because it is more generic, if someone have a similar question with properties which contains space characters for example.

Collectives™ on Stack Overflow

Grouped sorting on a JS array

4 Answers 4

2 Comments

3 Comments

Comments

3 Comments

Your Answer

Linked

Hot Network Questions

Collectives™ on Stack Overflow

4 Answers 4

2 Comments

3 Comments

Comments

3 Comments

Your Answer

Sign up or log in

Post as a guest

Linked

Related