arrays

javascript

sorting

numbers

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?

Solution 1

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.

Solution 2

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

Solution 3

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

To sort numbers, just create any TypedArray:

var numArray = new Float64Array([140000, 104, 99]);
numArray = numArray.sort();
console.log(numArray)

Solution 4

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.

Solution 5

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.

Solution 6

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.

Solution 7

just do .sort((a, b) => a - b) instead of .sort() itself

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

Solution 8

I agree with aks, however instead of using

return a - b;

You should use

return a > b ? 1 : a < b ? -1 : 0;

Solution 9

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();

Solution 10

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);

Solution 11

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

Solution 12

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

Solution 13

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;
   }
}

Solution 14

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]

Solution 15

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.

Solution 16

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}]**

Solution 17

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")

Solution 18

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>

Solution 19

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));

Solution 20

TypeScript variant

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

myArray.sort(compareNumbers)

Solution 21

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.

Solution 22

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)

Solution 23

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);

Solution 24

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)

Solution 25

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.

Solution 26

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

Solution 27

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;
});

Solution 28

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.

Solution 29

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

Solution 30

  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)