How to sort an array of integers correctly
Asked Answered
P

33

1419

Trying to get the highest and lowest value from an array that I know will contain only integers seems to be harder than I thought.

var numArray = [140000, 104, 99];
numArray = numArray.sort();
console.log(numArray)

I'd expect this to show 99, 104, 140000. Instead it shows 104, 140000, 99. So it seems the sort is handling the values as strings.

Is there a way to get the sort function to actually sort on integer value?

Pfennig answered 30/6, 2009 at 10:43 Comment(10)
BTW, if you're sorting lots and lots of integers it will be advantages to use an integer sort algorithm like counting sort. The time counting sort will take to run scales linearly with the size of your array: O(n). Whereas all solutions here use comparison sort which is less efficient: O(n * log n).Odisodium
@Odisodium Counting sort is linear regarding the number range, not the array. For example, sorting [1,1000000] will take more than 2 steps, since the algorithm will have to scan each array index between 1 to 1000000 to see which cell's value is greater than 0.Haffner
@Haffner Using a hashmap, you can only pay attention to the integers that show up in the array being sorted. This makes the sort linear wrt the array size.Lacustrine
the quickest way is to use the isomorphic sort-array module which works natively in both browser and node, supporting any type of input, computed fields and custom sort orders.Thorny
@Quuxplusone This question is about sorting numbers, and NaN is not a number. Dealing with NaN is only relevant in cases where you expect to have NaN, which is a small subset of cases in which we have an array of numbers.Gathers
@Web_Designer: Also using counting sort on [140000, 104, 99] will allocate and operate on arrays with 140000 elements. Beware!!Survive
It's pretty insane that JS still has this bug...Leander
@Leander it's not a bug, that's how Array.sort() is specified to work. But I agree that it's insane, one of the many quirks that make JavaScript not the greatest language in the world...Spancel
@Leander it's unreal, I honestly can't call it anything then a bug. If that's in the spec then they specified a bug in the specs. It's a bug.Wharve
I would really like to know the thought process that led to the conclusion "this is a good implementation of sort()".Subversive
G
2004

By default, the sort method sorts elements alphabetically. To sort numerically just add a new method which handles numeric sorts (sortNumber, shown below) -

var numArray = [140000, 104, 99];
numArray.sort(function(a, b) {
  return a - b;
});

console.log(numArray);

Documentation:

Mozilla Array.prototype.sort() recommends this compare function for arrays that don't contain Infinity or NaN. (Because Infinity - Infinity is NaN, not 0).

Also examples of sorting objects by key.

Glassman answered 30/6, 2009 at 10:47 Comment(24)
Nice. But is there really no out-of-the-box way to get a numerical sort from javascript?Pfennig
ahah this is out of the box! But if you're really impractical you can bind functions to the array class class at the very beginning of your javascript: // Array.prototype.sortNormal = function(){return this.sort(function(a,b){return a - b})} // Now calling .sortNormal() on any array will sort it numericallyHaematin
I have a requirement that it should not change the position of an array element when a = b. But above code changes array elements positions even though their values are same. Is there any workaround? ThanksBolick
Why a-b and not a>b. I suggest the last one in order to avoid operation machine errorsDupion
@Velthune The compare function should return -1, 0 or +1. a>b will only return true or false.Tingley
The compare function can return all the numeric value. The document: Array.prototype.sortMelanochroi
This code can be shortened using an Arrow Function. numberArray.sort((a, b) => (a - b)); Yay! I think this is close to the out-of-the-box way. Note: check if your JS engine supports Arrow Functions.Melanochroi
Javascript did not bother to implement number sort? What is the reasoning behind this?Superhuman
@K._ - I disagree that this is close to out of box way - you are using a side effect of the arrow syntax to cut out the words "function" and "return", but are not actually using the arrow function's true purpose of passing "this". I would strongly discourage others from using an arrow function here, as it implies there is some "this" context passing happening, but there isn't. Confusing for other developers to read your code, just to save a few chars.Diabolic
@K._ -- You don't actually need the parentheses: .sort((a, b) => a - b) -- so it's even shorter.Plumy
I don't understand why this works? Why even a - b and not a < b ?Sustain
@Sustain you should read the Array.prototype.sort() documentation page: developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/… You pass in a compare function to sort() that should return a value that's greater than zero, less than zero, or zero.Leban
@Sustain It's simply what sort()'s compare function expects. Have you read the linked documentation? When sort() runs, it accounts for three cases and a boolean expression doesn't suffice. When determining the order of two objects a and b, sort() determines that: (1) a comes before b, (2) b comes before a, or (3) a and b should be left in the order they came in with respect to each other but sorted with respect to the other elements in the array. Having the comparator function return a number that's > 0, 0 or < 0 maps to the described scenarios nicely.Leban
You can make a true numeric sort by using parseInt() around the inputs. This way it will also work with numeric filenames for example: numArray.sort((a, b) => parseInt(a) - parseInt(b));Sprain
@vikramvi sort() expects a negative number if b should go after a in the order, or a positive number if a should go after b. a-b is negative when b is bigger than a and should go after a, and positive when a is bigger than b and should go after. Using b-a reverses it - now it's negative when a is bigger than b and should go after a. Example: [1,9]: 1-9 = -8, so 9 should go after 1 in ascending order - conversely, 9-1 is 8, so 1 should go after 9 in descending order.Disclaimer
@JackFranzen This is absolutely not out of the box. It requires a very specific configuration of a function that is out of the box. The configuration itself is extremely unintuitive. If Javascript were better designed, .sort() would simply sort an array of integers correctly with none of this function passing nonsense.Gathers
@YungGun: And how would your hypothetical better design sort [42, '99', false, {x: 3}, new Rectangle(10, 5), /\s/g, 'true', new Date(1776, 6, 4)]?Foreshadow
@YungGun: I would hope that such an array wouldn't exist. Yet the language supports it; it's one of the downsides of dealing with a dynamically typed language. But you want a numeric sort. Someone else wants a case-insensitive descending sort. A third person wants to sort by date, ignoring time. Still someone else wants to sort by the 'age' property of their objects. Some idiot wants to sort that list above by the third character of elements' toString representation. Etc. It becomes really difficult to design any API that handles all this. But it's simpler to let the user decide.Foreshadow
Arrow functions are nice and shorter, but even without them the code can be written more concisely (in one line): numArray.sort(function(a, b) { return a - b; })Tabard
@IsaacCWay The reason modern Javascript requires you to pass functions is because most serious Javascript programmers deal with arrays of objects rather than just arrays of numbers. Take this for example var x = [{ title: "world", number: 10 }, { title: "hello", number: 5 }, { title: "world", number: 20 }, { title: "goodbye", number: 15 }]; I want this array to be sorted by the number value, but I will then output the title value in that order. console.log(x.sort((a, b) => a.number - b.number).map(x => x.title).join(" "));. In this case I chain three array functions to output the titles.Quartered
@SergioAbreu (or anyone with enough privilege) please undo the 2022-Aug-27 edit. (I tried but the queue is full.) The 13-year history of this answer and its comments are about the simple function a - b, not the function that compares a with Infinity and NaN. That new function belongs in a new answer (or nowhere, because it still returns NaN when a and b are both -Infinity or when b is NaN). Thanks!Whitaker
actually an insane person's idea of how .sort() should work for an array of numbersKiakiah
@ScottSauyet you should literally never have an array containing different types like thatGathers
@ICW: Certainly, you should never create one like that. Moreover, sorting it is a stupid idea. But as such things are possible in the language, generic language tools like Array.prototype.sort must be written to account for them.... Also, I've had some pretty terrible upstream systems I've had to deal with; haven't most of us?Foreshadow
G
222

Just building on all of the above answers, they can also be done in one line like this:

var numArray = [140000, 104, 99];
numArray = numArray.sort(function (a, b) {  return a - b;  });

//outputs: 99, 104, 140000
Gloriole answered 6/2, 2014 at 6:7 Comment(2)
I think you mean in one expression.Grantee
@bodyflex Fixed: var arr = [140000, 104, 99].sort(function(a,b) { return a-b; });. Or more compact, in ES6 let arr = [140000, 104, 99].sort((a,b) => a-b);Laudian
M
166

I am surprised why everyone recommends to pass a comparator function to sort(), that makes sorting slow.

To sort numbers, just create any TypedArray:

var numArray = new Float64Array([140000, 104, 99]);
numArray = numArray.sort();
console.log(numArray)
Miner answered 17/11, 2018 at 21:1 Comment(15)
Using a TypedArray speeds up sort by about 5X. If you want to go even faster hpc-algorithms npm package implements Radix Sort and Counting Sort that several answers here suggest.Blanding
I tried this with negative numbers and had a strange result: > new Uint32Array([ -4, -7, 1, 4 ]).sort() returned Uint32Array(4) [ 1, 4, 4294967289, 4294967292 ].Abidjan
@Nikolay D those are unsigned. You can use Int32Array.Venetic
sure sorting a typed array is faster. But if you have a regular array, converting it to a typed array to sort it is not a good solution (speed and memory)Kratz
@Kratz not sure that is true. Memory requirement is only O(2n) which is only a couple megabytes for an array of million items. As for speed - converting array to typedarray, sorting and converting back is still faster than sorting an array with a function.Miner
Using custom sorting function sort((a, b) => a - b) is very fast. The only benefit from using a Typed Array comes when dealing with huge arrays and it doesn't support dynamic size or push and instantiating one also takes more time than [] so it all depends on usage. I'd say if you're dealing with less than 20k element arrays don't bother with typed arrays.Tatman
The bad side with this answer - it returns an object - not a nice native array.Rene
@Rene just numArray = [...numArray] if you need plain array.Miner
It even supports infinities and NaN!Picul
This is both more efficient and more elegant. by now this is supported by all browsers, time to change the accepted answer for a better web. @PfennigTurtleneck
This is the right answer.Morra
This solution may be faster but has a narrower versatility. I have a case where, the data to be sorted is an array of object which contains some ids (integer). like [{id: 1}, {id:2}, ..] In this case you can't convert the array this way and still the only solution is use a custom functionCaramel
Funny how a bunch of people discuss performance here without (a) providing a runnable benchmark, (b) stating the browser / engine / OS / processor they are using and (c) providing any measured timings (averaged over many runs, also making null-hypothesis testing)Siliculose
Good answer. I didn't know the typed arrays in JS.Conjoin
"really slow"...Zuber
D
86

array.sort does a lexicographic sort by default, for a numeric sort, provide your own function. Here's a simple example:

function compareNumbers(a, b)
{
    return a - b;
}

numArray.sort(compareNumbers);

Also note that sort works "in place", there's no need for the assignment.

Denmark answered 30/6, 2009 at 10:47 Comment(3)
I didn't understand above code, how does "return a - b" does the ascending sorting ?Sudduth
if a < b, compareNumbers returns a negative number. If a > b, it will be positive. If equal, it returns 0.Denmark
@AliMertCakar because it only returns true or false, and the comparison function needs to return either a negative number, zero or a positive number.Denmark
H
79

This answer is equivalent to some of the existing answers, but ECMAScript 6 arrow functions provide a much more compact syntax that allows us to define an inline sort function without sacrificing readability:

numArray = numArray.sort((a, b) => a - b);

It is supported in most browsers today.

Helainehelali answered 3/2, 2016 at 20:7 Comment(0)
I
47

just do .sort((a, b) => a - b) instead of .sort() itself. In addition to that the array is sorted in place. So return value does not matter.

var numArray = [140000, 104, 99];
numArray.sort((a, b) => a - b);
console.log(numArray)
Inhibition answered 20/9, 2021 at 7:55 Comment(0)
S
35

The reason why the sort function behaves so weird

From the documentation:

[...] the array is sorted according to each character's Unicode code point value, according to the string conversion of each element.

If you print the unicode point values of the array then it will get clear.

console.log("140000".charCodeAt(0));
console.log("104".charCodeAt(0));
console.log("99".charCodeAt(0));

//Note that we only look at the first index of the number "charCodeAt(  0  )"

This returns: "49, 49, 57".

49 (unicode value of first number at 140000)
49 (unicode value of first number at 104)
57 (unicode value of first number at 99)

Now, because 140000 and 104 returned the same values (49) it cuts the first index and checks again:

console.log("40000".charCodeAt(0));
console.log("04".charCodeAt(0));

//Note that we only look at the first index of the number "charCodeAt(  0  )"
52 (unicode value of first number at 40000)
40 (unicode value of first number at 04)

If we sort this, then we will get:

40 (unicode value of first number at 04)
52 (unicode value of first number at 40000)

so 104 comes before 140000.

So the final result will be:

var numArray = [140000, 104, 99];
numArray = numArray.sort();
console.log(numArray)

104, 140000, 99

Conclusion:

sort() does sorting by only looking at the first index of the numbers. sort() does not care if a whole number is bigger than another, it compares the value of the unicode of the digits, and if there are two equal unicode values, then it checks if there is a next digit and compares it as well.

To sort correctly, you have to pass a compare function to sort() like explained here.

Sustain answered 26/5, 2018 at 7:7 Comment(1)
Hint: This is only my explanation, I did not actually looked up the code. So don't fully trust this answer.Sustain
F
22

Ascending

arr.sort((a, b) => a - b);

Descending

arr.sort((a, b) => b - a);

Just for fun:

Descending = Ascending + Reverse

arr.sort((a, b) => a - b).reverse();
Foliolate answered 30/8, 2021 at 6:57 Comment(0)
C
18

Array.sort uses alphabetic sorting by default instead of numeric .

To support numbers, add like following

var numArray = [140000, 104, 99];
numArray.sort((a, b) =>  a - b); // <-- Ascending
numArray.sort((a, b) =>  b - a); // <-- Descending
console.log(numArray);

OUTPUT :

Array Numeric Sorting

Cobol answered 27/7, 2022 at 11:31 Comment(0)
U
15

I agree with aks, however instead of using

return a - b;

You should use

return a > b ? 1 : a < b ? -1 : 0;
Uella answered 30/6, 2009 at 10:43 Comment(12)
Can you explain why anyone should use your more unreadable ternary operation? As far as I can tell it would have the same result.Annular
This answer also takes equal values into consideration and leaves them in the same place.Chenoweth
well, even though this answer doesn't contribute anything esle to the topic it doesn't deserve to get -1. All in all it is a valid answer, redendant but valid.Wafer
"return a-b" may be adequate for the particular case of this question (javascript, and all input items known to be ints), but personally I prefer the ternary form because it's more canonical-- it works in more cases, in more programming languages, with more data types. E.g. in C, a-b can overflow, leading to the sort endless looping, corrupting memory, crashing, etc. That said, even the ternary form isn't going to work sanely if there are NaNs or mixed types involved.Criswell
The > and < still compare a and b as strings.Cervical
Maybe a minor quibble, but: In javascript, there's only one numeric type; everything is a float.Milena
return +(a > b) || -(a < b);Lucianaluciano
@Annular There is one case where this answer returns the correct evaluation for numbers where a - b doesnt. Where a = b = -Infinity, a - b = NaN, but the ternary returns 0. But this doesn't seem to affect the sort, it still does it perfectly. (a > b) - (a < b) is a shorter version that is equivalent to this ternary.Osteogenesis
@Cervical no they don't?Zeus
@RomanStarkov the point was that neither a<b nor a>b coerces the string elements into numbers whereas a-b does.Cibis
@Cervical @wOxxom I don't think a or b are strings in the sort fn; e.g. [101, 3, -15].sort((a, b) => { console.log(typeof a); return a - b }) outputs number some number of times (depending on the browser) and sorts the values correctly.Chiffonier
This version works just as well with strings ("a" - "b" is NaN, but string comparisons with < and > work as expected).Hajji
C
13

The question has already been answered, the shortest way is to use sort() method. But if you're searching for more ways to sort your array of numbers, and you also love cycles, check the following

Insertion sort

Ascending:

var numArray = [140000, 104, 99];
for (var i = 0; i < numArray.length; i++) {
    var target = numArray[i];
    for (var j = i - 1; j >= 0 && (numArray[j] > target); j--) {
        numArray[j+1] = numArray[j];
    }
    numArray[j+1] = target
}
console.log(numArray);

Descending:

var numArray = [140000, 104, 99];
for (var i = 0; i < numArray.length; i++) {
    var target = numArray[i];
    for (var j = i - 1; j >= 0 && (numArray[j] < target); j--) {
        numArray[j+1] = numArray[j];
    }
    numArray[j+1] = target
}
console.log(numArray);

Selection sort:

Ascending:

var numArray = [140000, 104, 99];
for (var i = 0; i < numArray.length - 1; i++) {
    var min = i;
    for (var j = i + 1; j < numArray.length; j++) {
        if (numArray[j] < numArray[min]) {
            min = j;
        }
    }
    if (min != i) {
        var target = numArray[i];
        numArray[i] = numArray[min];
        numArray[min] = target;
    }
}
console.log(numArray);

Descending:

var numArray = [140000, 104, 99];
for (var i = 0; i < numArray.length - 1; i++) {
    var min = i;
    for (var j = i + 1; j < numArray.length; j++) {
        if (numArray[j] > numArray[min]) {
            min = j;
        }
    }
    if (min != i) {
        var target = numArray[i];
        numArray[i] = numArray[min];
        numArray[min] = target;
    }
}
console.log(numArray);

Have fun

Concordance answered 26/6, 2016 at 18:34 Comment(1)
Are any of these actually faster for tiny arrays than using sort() on a TypedArray like this answer suggests. Certainly they won't be faster for medium to large arrays because these are O(n^2) algorithms.Kallman
P
12

In JavaScript the sort() method's default behaviour is to sort values in an array alphabetically.

To sort by number you have to define a numeric sort function (which is very easy):

...
function sortNumber(a, b)
{
  return a - b;
}

numArray = numArray.sort(sortNumber);
Piefer answered 30/6, 2009 at 10:48 Comment(0)
L
9

Array.prototype.sort() is the go to method for sorting arrays, but there are a couple of issues we need to be aware of.

The sorting order is by default lexicographic and not numeric regardless of the types of values in the array. Even if the array is all numbers, all values will be converted to string and sorted lexicographically.

So should we need to customize the sort() and reverse() method like below.

Referred URL

For sorting numbers inside the array

numArray.sort(function(a, b)
{
    return a - b;
});

For reversing numbers inside the array

numArray.sort(function(a, b)
{
    return b - a;
});

Referred URL

Lunarian answered 2/3, 2016 at 7:53 Comment(0)
P
9

The function 'numerically' below serves the purpose of sorting array of numbers numerically in many cases when provided as a callback function:

function numerically(a, b){
    return a-b;
}

array.sort(numerically); 

But in some rare instances, where array contains very large and negative numbers, an overflow error can occur as the result of a-b gets smaller than the smallest number that JavaScript can cope with.

So a better way of writing numerically function is as follows:

function numerically(a, b){
   if(a < b){
      return -1;
   } else if(a > b){
      return 1;
   } else {
      return 0;
   }
}
Pram answered 26/1, 2019 at 7:58 Comment(1)
JavaScript numbers are floating-point. IEEE754 defines overflow and underflow rules, including overflow to +-Infinity, and underflow to subnormal or +-0.0. I don't think subtraction of two numbers can underflow to +-0.0 even if they're both large and nearby equal. The difference between two doubles is always representable as another non-zero double (unless it overflows, like DBL_MIN - DBL_MAX) but underflow isn't possible. Catastrophic cancellation makes the result imprecise, losing most of its "significant digits", but a-b will always be non-zero and have the right sign for a!=b.Kallman
W
6

to handle undefined, null, and NaN: Null behaves like 0, NaN and undefined goes to end.

array = [3, 5, -1, 1, NaN, 6, undefined, 2, null]
array.sort((a,b) => isNaN(a) || a-b)
// [-1, null, 1, 2, 3, 5, 6, NaN, undefined]
Wizened answered 11/10, 2018 at 22:40 Comment(2)
The language spec requires that the compare function always return a number other than NaN when called on any two elements of the array. This function returns NaN when b is NaN or undefined, and when a and b are both Infinity or both -Infinity.Whitaker
The idea to check for NaN is not bad but this code doesn't put NaNs to the endKelley
W
5

The accepted answer and equivalents like numArray.sort((a,b) => a - b) are great when the array contains only numbers without infinities or NaN. They can be extended to handle infinities and NaN like so:

numArray.sort((a,b) => (+a || 0) - (+b || 0) || 0);

This sorts NaN (or any non-number, like 'foo' or {}) as if it were 0. The final || 0 is needed to handle the case where a and b are equal infinities.

Whitaker answered 20/7, 2021 at 7:26 Comment(0)
H
4

While not required in JavaScript, if you would like the sort() compareFunction to strictly return -1, 0, or 1 (similar to how the spaceship operator works in PHP), then you can use Math.sign().

The compareFunction below strictly returns -1, 0, or 1:

numArray.sort((a, b) => Math.sign(a - b));

Note: Math.sign() is not supported in Internet Explorer.

Hoseahoseia answered 29/2, 2020 at 15:56 Comment(0)
B
3

For a normal array of elements values only:

function sortArrayOfElements(arrayToSort) {
    function compareElements(a, b) {
        if (a < b)
            return -1;
        if (a > b)
            return 1;
        return 0;
    }

    return arrayToSort.sort(compareElements);
}

e.g. 1:
var array1 = [1,2,545,676,64,2,24]
**output : [1, 2, 2, 24, 64, 545, 676]**

var array2 = ["v","a",545,676,64,2,"24"]
**output: ["a", "v", 2, "24", 64, 545, 676]**

For an array of objects:

function sortArrayOfObjects(arrayToSort, key) {
    function compareObjects(a, b) {
        if (a[key] < b[key])
            return -1;
        if (a[key] > b[key])
            return 1;
        return 0;
    }

    return arrayToSort.sort(compareObjects);
}

e.g. 1: var array1= [{"name": "User4", "value": 4},{"name": "User3", "value": 3},{"name": "User2", "value": 2}]

**output : [{"name": "User2", "value": 2},{"name": "User3", "value": 3},{"name": "User4", "value": 4}]**
Bechler answered 7/2, 2018 at 11:4 Comment(0)
S
3

In order to create this kind of sort, you have to pass a function that will check which comes first.

define inside the function which value do you wanna check: a.id - a.id

        const myJson = [
            { id: 1, name: 'one'},
            { id: 4, name: 'four'},
            { id: 2, name: 'two'},
            { id: 3, name: 'three'}
        ];

        // provide the sort method to check
        const myNewSort = myJson.sort(function(a, b) {
          return a.id - b.id;
        });

        console.log('my new sort',myNewSort)
Shuster answered 13/9, 2021 at 19:32 Comment(0)
B
2

Update! Scroll to bottom of answer for smartSort prop additive that gives even more fun!
Sorts arrays of anything!

My personal favorite form of this function allows for a param for Ascending, or Descending:

function intArraySort(c, a) {
    function d(a, b) { return b - a; }
    "string" == typeof a && a.toLowerCase();
    switch (a) {
        default: return c.sort(function(a, b) { return a - b; });
        case 1:
                case "d":
                case "dc":
                case "desc":
                return c.sort(d)
    }
};

Usage as simple as:

var ara = function getArray() {
        var a = Math.floor(Math.random()*50)+1, b = [];
        for (i=0;i<=a;i++) b.push(Math.floor(Math.random()*50)+1);
        return b;
    }();

//    Ascending
intArraySort(ara);
console.log(ara);

//    Descending
intArraySort(ara, 1);
console.log(ara);

//    Ascending
intArraySort(ara, 'a');
console.log(ara);

//    Descending
intArraySort(ara, 'dc');
console.log(ara);

//    Ascending
intArraySort(ara, 'asc');
console.log(ara);

jsFiddle


Or Code Snippet Example Here!

function intArraySort(c, a) {
	function d(a, b) { return b - a }
	"string" == typeof a && a.toLowerCase();
	switch (a) {
		default: return c.sort(function(a, b) { return a - b });
		case 1:
		case "d":
		case "dc":
		case "desc":
		return c.sort(d)
	}
};

function tableExample() {
	var d = function() {
			var a = Math.floor(50 * Math.random()) + 1,
				b = [];
			for (i = 0; i <= a; i++) b.push(Math.floor(50 * Math.random()) + 1);
			return b
		},
		a = function(a) {
			var b = $("<tr/>"),
				c = $("<th/>").prependTo(b);
			$("<td/>", {
				text: intArraySort(d(), a).join(", ")
			}).appendTo(b);
			switch (a) {
				case 1:
				case "d":
				case "dc":
				case "desc":
					c.addClass("desc").text("Descending");
					break;
				default:
					c.addClass("asc").text("Ascending")
			}
			return b
		};
	return $("tbody").empty().append(a(), a(1), a(), a(1), a(), a(1), a(), a(1), a(), a(1), a(), a(1))
};

tableExample();
table { border-collapse: collapse; }
th, td { border: 1px solid; padding: .25em .5em; vertical-align: top; }
.asc { color: red; }
.desc { color: blue }
<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.9.1/jquery.min.js"></script>
<table><tbody></tbody></table>

.smartSort('asc' | 'desc')

Now have even more fun with a sorting method that sorts an array full of multiple items! Doesn't currently cover "associative" (aka, string keys), but it does cover about every type of value! Not only will it sort the multiple values asc or desc accordingly, but it will also maintain constant "position" of "groups" of values. In other words; ints are always first, then come strings, then arrays (yes, i'm making this multidimensional!), then Objects (unfiltered, element, date), & finally undefineds and nulls!

"Why?" you ask. Why not!

Now comes in 2 flavors! The first of which requires newer browsers as it uses Object.defineProperty to add the method to the Array.protoype Object. This allows for ease of natural use, such as: myArray.smartSort('a'). If you need to implement for older browsers, or you simply don't like modifying native Objects, scroll down to Method Only version.

/* begin */
/* KEY NOTE! Requires EcmaScript 5.1 (not compatible with older browsers) */
;;(function(){if(Object.defineProperty&&!Array.prototype.smartSort){var h=function(a,b){if(null==a||void 0==a)return 1;if(null==b||void 0==b)return-1;var c=typeof a,e=c+typeof b;if(/^numbernumber$/ig.test(e))return a-b;if(/^stringstring$/ig.test(e))return a>b;if(/(string|number){2}/ig.test(e))return/string/i.test(c)?1:-1;if(/number/ig.test(e)&&/object/ig.test(e)||/string/ig.test(e)&&/object/ig.test(e))return/object/i.test(c)?1:-1;if(/^objectobject$/ig.test(e)){a instanceof Array&&a.smartSort("a");b instanceof Array&&b.smartSort("a");if(a instanceof Date&&b instanceof Date)return a-b;if(a instanceof Array&&b instanceof Array){var e=Object.keys(a),g=Object.keys(b),e=e.concat(g).smartSort("a"),d;for(d in e)if(c=e[d],a[c]!=b[c])return d=[a[c],b[c]].smartSort("a"),a[c]==d[0]?-1:1;var f=[a[Object.keys(a)[0]],b[Object.keys(b)[0]]].smartSort("a");return a[Object.keys(a)[0]]==f[0]?-1:1}if(a instanceof Element&&b instanceof Element){if(a.tagName==b.tagName)return e=[a.id,b.id].smartSort("a"),a.id==e[0]?1:-1;e=[a.tagName, b.tagName].smartSort("a");return a.tagName==e[0]?1:-1}if(a instanceof Date||b instanceof Date)return a instanceof Date?1:-1;if(a instanceof Array||b instanceof Array)return a instanceof Array?-1:1;e=Object.keys(a);g=Object.keys(b);e.concat(g).smartSort("a");for(c=0;20>c;c++){d=e[c];f=g[c];if(a.hasOwnProperty(d)&&b.hasOwnProperty(f)){if(a[d]instanceof Element&&b[f]instanceof Element){if(a[d].tagName==b[f].tagName)return c=[a[d].id,b[f].id].smartSort("a"),a[d].id==c[0]?-1:1;c=[a[d].tagName,b[f].tagName].smartSort("d"); return a[d].tagName==c[0]?1:-1}if(a[d]instanceof Element||b[f]instanceof Element)return a[d]instanceof Element?1:-1;if(a[d]!=b[f])return c=[a[d],b[f]].smartSort("a"),a[d]==c[0]?-1:1}if(a.hasOwnProperty(d)&&a[d]instanceof Element)return 1;if(b.hasOwnProperty(f)&&b[f]instanceof Element||!a.hasOwnProperty(d))return-1;if(!b.hasOwnProperty(d))return 1}c=[a[Object.keys(a)[0]],b[Object.keys(b)[0]]].smartSort("d");return a[Object.keys(a)[0]]==c[0]?-1:1}g=[a,b].sort();return g[0]>g[1]},k=function(a,b){if(null== a||void 0==a)return 1;if(null==b||void 0==b)return-1;var c=typeof a,e=c+typeof b;if(/^numbernumber$/ig.test(e))return b-a;if(/^stringstring$/ig.test(e))return b>a;if(/(string|number){2}/ig.test(e))return/string/i.test(c)?1:-1;if(/number/ig.test(e)&&/object/ig.test(e)||/string/ig.test(e)&&/object/ig.test(e))return/object/i.test(c)?1:-1;if(/^objectobject$/ig.test(e)){a instanceof Array&&a.smartSort("d");b instanceof Array&&b.smartSort("d");if(a instanceof Date&&b instanceof Date)return b-a;if(a instanceof Array&&b instanceof Array){var e=Object.keys(a),g=Object.keys(b),e=e.concat(g).smartSort("a"),d;for(d in e)if(c=e[d],a[c]!=b[c])return d=[a[c],b[c]].smartSort("d"),a[c]==d[0]?-1:1;var f=[a[Object.keys(a)[0]],b[Object.keys(b)[0]]].smartSort("d");return a[Object.keys(a)[0]]==f[0]?-1:1}if(a instanceof Element&&b instanceof Element){if(a.tagName==b.tagName)return e=[a.id,b.id].smartSort("d"),a.id==e[0]?-1:1;e=[a.tagName,b.tagName].smartSort("d");return a.tagName==e[0]?-1:1}if(a instanceof Date||b instanceof Date)return a instanceof Date?1:-1;if(a instanceof Array||b instanceof Array)return a instanceof Array?-1:1;e=Object.keys(a);g=Object.keys(b);e.concat(g).smartSort("a");for(c=0;20>c;c++){d=e[c];f=g[c];if(a.hasOwnProperty(d)&&b.hasOwnProperty(f)){if(a[d]instanceof Element&&b[f]instanceof Element){if(a[d].tagName==b[f].tagName)return c=[a[d].id,b[f].id].smartSort("d"),a[d].id==c[0]?-1:1;c=[a[d].tagName,b[f].tagName].smartSort("d");return a[d].tagName==c[0]?-1:1}if(a[d]instanceof Element||b[f]instanceof Element)return a[d]instanceof Element?1:-1;if(a[d]!=b[f])return c=[a[d],b[f]].smartSort("d"),a[d]==c[0]?-1:1}if(a.hasOwnProperty(d)&&a[d]instanceof Element)return 1;if(b.hasOwnProperty(f)&&b[f]instanceof Element)return-1;if(!a.hasOwnProperty(d))return 1;if(!b.hasOwnProperty(d))return-1}c=[a[Object.keys(a)[0]],b[Object.keys(b)[0]]].smartSort("d");return a[Object.keys(a)[0]]==c[0]?-1:1}g=[a,b].sort();return g[0]<g[1]};Object.defineProperty(Array.prototype,"smartSort",{value:function(){return arguments&& (!arguments.length||1==arguments.length&&/^a([sc]{2})?$|^d([esc]{3})?$/i.test(arguments[0]))?this.sort(!arguments.length||/^a([sc]{2})?$/i.test(arguments[0])?h:k):this.sort()}})}})();
/* end */

jsFiddle Array.prototype.smartSort('asc|desc')


Use is simple! First make some crazy array like:

window.z = [ 'one', undefined, $('<span />'), 'two', null, 2, $('<div />', { id: 'Thing' }), $('<div />'), 4, $('<header />') ];
z.push(new Date('1/01/2011'));
z.push('three');
z.push(undefined);
z.push([ 'one', 'three', 'four' ]);
z.push([ 'one', 'three', 'five' ]);
z.push({ a: 'a', b: 'b' });
z.push({ name: 'bob', value: 'bill' });
z.push(new Date());
z.push({ john: 'jill', jack: 'june' });
z.push([ 'abc', 'def', [ 'abc', 'def', 'cba' ], [ 'cba', 'def', 'bca' ], 'cba' ]);
z.push([ 'cba', 'def', 'bca' ]);
z.push({ a: 'a', b: 'b', c: 'c' });
z.push({ a: 'a', b: 'b', c: 'd' });

Then simply sort it!

z.smartSort('asc'); // Ascending
z.smartSort('desc'); // Descending

Method Only

Same as the preceding, except as just a simple method!

/* begin */
/* KEY NOTE! Method `smartSort` is appended to native `window` for global use. If you'd prefer a more local scope, simple change `window.smartSort` to `var smartSort` and place inside your class/method */
window.smartSort=function(){if(arguments){var a,b,c;for(c in arguments)arguments[c]instanceof Array&&(a=arguments[c],void 0==b&&(b="a")),"string"==typeof arguments[c]&&(b=/^a([sc]{2})?$/i.test(arguments[c])?"a":"d");if(a instanceof Array)return a.sort("a"==b?smartSort.asc:smartSort.desc)}return this.sort()};smartSort.asc=function(a,b){if(null==a||void 0==a)return 1;if(null==b||void 0==b)return-1;var c=typeof a,e=c+typeof b;if(/^numbernumber$/ig.test(e))return a-b;if(/^stringstring$/ig.test(e))return a> b;if(/(string|number){2}/ig.test(e))return/string/i.test(c)?1:-1;if(/number/ig.test(e)&&/object/ig.test(e)||/string/ig.test(e)&&/object/ig.test(e))return/object/i.test(c)?1:-1;if(/^objectobject$/ig.test(e)){a instanceof Array&&a.sort(smartSort.asc);b instanceof Array&&b.sort(smartSort.asc);if(a instanceof Date&&b instanceof Date)return a-b;if(a instanceof Array&&b instanceof Array){var e=Object.keys(a),g=Object.keys(b),e=smartSort(e.concat(g),"a"),d;for(d in e)if(c=e[d],a[c]!=b[c])return d=smartSort([a[c], b[c]],"a"),a[c]==d[0]?-1:1;var f=smartSort([a[Object.keys(a)[0]],b[Object.keys(b)[0]]],"a");return a[Object.keys(a)[0]]==f[0]?-1:1}if(a instanceof Element&&b instanceof Element){if(a.tagName==b.tagName)return e=smartSort([a.id,b.id],"a"),a.id==e[0]?1:-1;e=smartSort([a.tagName,b.tagName],"a");return a.tagName==e[0]?1:-1}if(a instanceof Date||b instanceof Date)return a instanceof Date?1:-1;if(a instanceof Array||b instanceof Array)return a instanceof Array?-1:1;e=Object.keys(a);g=Object.keys(b);smartSort(e.concat(g), "a");for(c=0;20>c;c++){d=e[c];f=g[c];if(a.hasOwnProperty(d)&&b.hasOwnProperty(f)){if(a[d]instanceof Element&&b[f]instanceof Element){if(a[d].tagName==b[f].tagName)return c=smartSort([a[d].id,b[f].id],"a"),a[d].id==c[0]?-1:1;c=smartSort([a[d].tagName,b[f].tagName],"a");return a[d].tagName==c[0]?-1:1}if(a[d]instanceof Element||b[f]instanceof Element)return a[d]instanceof Element?1:-1;if(a[d]!=b[f])return c=smartSort([a[d],b[f]],"a"),a[d]==c[0]?-1:1}if(a.hasOwnProperty(d)&&a[d]instanceof Element)return 1; if(b.hasOwnProperty(f)&&b[f]instanceof Element||!a.hasOwnProperty(d))return-1;if(!b.hasOwnProperty(d))return 1}c=smartSort([a[Object.keys(a)[0]],b[Object.keys(b)[0]]],"a");return a[Object.keys(a)[0]]==c[0]?1:-1}g=[a,b].sort();return g[0]>g[1]};smartSort.desc=function(a,b){if(null==a||void 0==a)return 1;if(null==b||void 0==b)return-1;var c=typeof a,e=c+typeof b;if(/^numbernumber$/ig.test(e))return b-a;if(/^stringstring$/ig.test(e))return b>a;if(/(string|number){2}/ig.test(e))return/string/i.test(c)? 1:-1;if(/number/ig.test(e)&&/object/ig.test(e)||/string/ig.test(e)&&/object/ig.test(e))return/object/i.test(c)?1:-1;if(/^objectobject$/ig.test(e)){a instanceof Array&&a.sort(smartSort.desc);b instanceof Array&&b.sort(smartSort.desc);if(a instanceof Date&&b instanceof Date)return b-a;if(a instanceof Array&&b instanceof Array){var e=Object.keys(a),g=Object.keys(b),e=smartSort(e.concat(g),"a"),d;for(d in e)if(c=e[d],a[c]!=b[c])return d=smartSort([a[c],b[c]],"d"),a[c]==d[0]?-1:1;var f=smartSort([a[Object.keys(a)[0]], b[Object.keys(b)[0]]],"d");return a[Object.keys(a)[0]]==f[0]?-1:1}if(a instanceof Element&&b instanceof Element){if(a.tagName==b.tagName)return e=smartSort([a.id,b.id],"d"),a.id==e[0]?-1:1;e=smartSort([a.tagName,b.tagName],"d");return a.tagName==e[0]?-1:1}if(a instanceof Date||b instanceof Date)return a instanceof Date?1:-1;if(a instanceof Array||b instanceof Array)return a instanceof Array?-1:1;e=Object.keys(a);g=Object.keys(b);smartSort(e.concat(g),"a");for(c=0;20>c;c++){d=e[c];f=g[c];if(a.hasOwnProperty(d)&& b.hasOwnProperty(f)){if(a[d]instanceof Element&&b[f]instanceof Element){if(a[d].tagName==b[f].tagName)return c=smartSort([a[d].id,b[f].id],"d"),a[d].id==c[0]?-1:1;c=smartSort([a[d].tagName,b[f].tagName],"d");return a[d].tagName==c[0]?-1:1}if(a[d]instanceof Element||b[f]instanceof Element)return a[d]instanceof Element?1:-1;if(a[d]!=b[f])return c=smartSort([a[d],b[f]],"d"),a[d]==c[0]?-1:1}if(a.hasOwnProperty(d)&&a[d]instanceof Element)return 1;if(b.hasOwnProperty(f)&&b[f]instanceof Element)return-1; if(!a.hasOwnProperty(d))return 1;if(!b.hasOwnProperty(d))return-1}c=smartSort([a[Object.keys(a)[0]],b[Object.keys(b)[0]]],"d");return a[Object.keys(a)[0]]==c[0]?-1:1}g=[a,b].sort();return g[0]<g[1]}
/* end */

Use:

z = smartSort(z, 'asc'); // Ascending
z = smartSort(z, 'desc'); // Descending

jsFiddle Method smartSort(Array, "asc|desc")

Boatwright answered 7/12, 2014 at 19:2 Comment(0)
S
2

Try this code:

HTML:

<div id="demo"></div>

JavaScript code:

<script>
    (function(){
        var points = [40, 100, 1, 5, 25, 10];
        document.getElementById("demo").innerHTML = points;
        points.sort(function(a, b){return a-b});
        document.getElementById("demo").innerHTML = points;
    })();
</script>
Sangfroid answered 17/11, 2015 at 5:48 Comment(0)
O
2

Try this code as below

var a = [5, 17, 29, 48, 64, 21];
function sortA(arr) {
return arr.sort(function(a, b) {
return a - b;
})
;} 
alert(sortA(a));
Offense answered 7/2, 2018 at 10:58 Comment(0)
C
2

TypeScript variant

const compareNumbers = (a: number, b: number): number => a - b

myArray.sort(compareNumbers)
Camiecamila answered 15/1, 2021 at 17:46 Comment(0)
F
1

You can sort number array simply by

const num=[13,17,14,19,16];
let temp;
for(let i=0;i<num.length;i++){
    for(let j=i+1;j<num.length;j++){
        if(num[i]>num[j]){
            temp=num[i]
            num[i]=num[j]
            num[j]=temp
        }
    }
}

console.log(num);
Farica answered 1/11, 2020 at 9:18 Comment(2)
Question is how to sort numbers using array method sort().Idea
i cannot see something like that in the questionFarica
L
1

You can get height and lowest number simply by using max() and min() in-built function

var numArray = [140000, 104, 99];
console.log(Math.max(...numArray));
console.log(Math.min(...numArray));

If you want to sort in ascending or descending order

numArray.sort((a, b)=> a - b);

Know more

Lamonica answered 18/6, 2021 at 22:4 Comment(0)
D
1

let grade =[80,100,50,90,40];
grade.sort((x,y)=> x-y);
grade.forEach(element=>console.log(element));
Danielson answered 13/9, 2022 at 7:50 Comment(0)
S
0

As sort method converts Array elements into string. So, below way also works fine with decimal numbers with array elements.

let productPrices = [10.33, 2.55, 1.06, 5.77];
console.log(productPrices.sort((a,b)=>a-b));

And gives you the expected result.

Scoles answered 22/11, 2019 at 6:9 Comment(1)
“As sort method converts Array elements into string.” — No, it doesn’t.Rutherfurd
R
0

Sort integers > 0, think outside the box:

function sortArray(arr) {
  return new Promise((resolve) => {
    const result = []
    arr.forEach((item) => {
      setTimeout(() => {
        result.push(item)
        if (result.length === arr.length) resolve(result)
      }, item)
    })
  })
}

sortArray([4, 2, 42, 128, 56, 2]).then((result) => {
  document.write(JSON.stringify(result))
})

Note that this should not be used productively, .sort() is better suited for this, check the other answers

Raskind answered 27/8, 2020 at 8:42 Comment(1)
Can you explain why to use asynchronous call to sort numbers?Idea
E
0

sort_mixed

Object.defineProperty(Array.prototype,"sort_mixed",{
    value: function () { // do not use arrow function
        var N = [], L = [];
        this.forEach(e => {
            Number.isFinite(e) ? N.push(e) : L.push(e);
        });
        N.sort((a, b) => a - b);
        L.sort();
        [...N, ...L].forEach((v, i) => this[i] = v);
        return this;
    })

try a =[1,'u',"V",10,4,"c","A"].sort_mixed(); console.log(a)

Extrinsic answered 16/9, 2020 at 21:36 Comment(0)
A
0

If anyone doesn't understand how Array.sort() works with integers, read this answer.

Alphabetical order:

By default, the sort() method sorts the values as strings in alphabetical and ascending order.

const myArray = [104, 140000, 99];
myArray.sort();
console.log(myArray); // output is [104, 140000, 99]

Ascending order with array.sort(compareFunction):

const myArray = [104, 140000, 99];
myArray.sort(function(a, b){
  return a - b;
});
console.log(myArray); // output is [99, 104, 140000]

Explanation from w3schools:

compareFunction defines an alternative sort order. The function should return a negative, zero, or positive value, depending on the arguments, like: function(a, b){return a-b} When the sort() method compares two values, it sends the values to the compare function, and sorts the values according to the returned (negative, zero, positive) value.

Example:

When comparing 40 and 100, the sort() method calls the compare function(40,100).

The function calculates 40-100, and returns -60 (a negative value).

The sort function will sort 40 as a value lower than 100.

Descending order with array.sort(compareFunction):

const myArray = [104, 140000, 99];
myArray.sort(function(a, b){
  return b - a;
});
console.log(myArray); // output is [140000, 104, 99]

This time we calculated with b - a(i.e., 100-40) which returns a positive value.

Afterheat answered 22/9, 2020 at 9:55 Comment(0)
D
0

If you need to calculate and sort the largest charCodeAt from a list of string this is the right way.

const arrayLines = '1.1.1.1\n1.0.1.1\n1.1.1.2\n1.1.1.0'.split('\n');

// Response: (4) ['1.0.1.1', '1.1.1.0', '1.1.1.1', '1.1.1.2']
arrayLines.sort((a, b) => {
    let a_charCodeSize = 0,
        b_charCodeSize = 0;

    // Loop true a & b characters and calculate the charCodeAt size.
    for (const aChar of a) a_charCodeSize += aChar.charCodeAt(0);
    for (const bChar of b) b_charCodeSize += bChar.charCodeAt(0);

    return a_charCodeSize - b_charCodeSize;
});
Dvinsk answered 6/10, 2021 at 0:8 Comment(5)
why the need to write any implementation, javascript sort natively does exactly same thing, it compares strings by their character code from starting index and moves forward. arrayLines.sort() responses same way, without passing any custom functionDibromide
@SajidAli Natively sort does not compare all characters one by one but instead evaluate the whole value given. Which will not result in a correct response in that scenario.Dvinsk
try native sort in above example and see... sort() sorts the elements of array in place and returns sorted array. Default sort order is ascending, built upon converting the elements into strings, then comparing their sequences of UTF-16 code units values If function is not supplied, all non-undefined array elements are sorted by converting them to strings and comparing strings in UTF-16 code units order. For example, "banana" comes before "cherry". In a numeric sort, 9 comes before 80, but because numbers are converted to strings, "80" comes before "9" in the Unicode order. ref: MDNDibromide
@SajidAli i tried it but it doesn't produce the desired output. sort using a-b is returning ['1.1.1.1', '1.0.1.1', '1.1.1.2', '1.1.1.0'] which makes no sense.Dvinsk
that's your problem right there. no need to add a-b at all, just use sort without passing any callback function. arrayLines.sort(), and it will show you same result as you got by implementing your own custom callback methodDibromide
P
0

This can be done with localeCompare using either options or locales tag:

const numArray = [140000, 104, 99, 3, 2, 12, 25, 10, 1]

console.log('Using options:',
  numArray.sort((a, b) => a.toString().localeCompare(b, undefined, { numeric: true })),
)

console.log('Using locales tag:',
  numArray.sort((a, b) => a.toString().localeCompare(b, 'en-u-kn-true')),
)
Phraseogram answered 26/3 at 9:39 Comment(0)
A
-1
  1. Ascending

    const movements = [200, 450, -400, 3000, -650, -130, 70, 1300];

If we return something < 0 then A will be before B If we return something > 0 then B will be before A

 movements.sort((a, b) => {
      if (a > b) return 1; //- (Switch order)
      if (a < b) return -1; //- (Keep order)
    });

a - current value, b - the next value.

  1. Descending

    movements.sort((a, b) => { if (a > b) return -1; // - (Keep) if (a < b) return 1; // - (Switch) });

! Improve, best solution !

movements.sort ((a, b) => a - b); // Same result!

If a < b it's negative number(Switch) If a < b it's negative number(Keep)

Amby answered 30/6, 2009 at 10:43 Comment(1)
Your last bit has a typo, leading to a oxymoron. Your first bit does not address the situation where a==b. To format inline code, isurrounded it by single backtics.Wagshul

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