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)
_x000D_
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?
This question is related to
javascript
arrays
sorting
numbers
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);
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));_x000D_
console.log("104".charCodeAt(0));_x000D_
console.log("99".charCodeAt(0));_x000D_
_x000D_
//Note that we only look at the first index of the number "charCodeAt( 0 )"
_x000D_
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));_x000D_
console.log("04".charCodeAt(0));_x000D_
_x000D_
//Note that we only look at the first index of the number "charCodeAt( 0 )"
_x000D_
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];_x000D_
numArray = numArray.sort();_x000D_
console.log(numArray)
_x000D_
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.
This is the already proposed and accepted solution as a method on the Array prototype:
Array.prototype.sortNumeric = function () {
return this.sort((a, b) => a - b);
};
Array.prototype.sortNumericDesc = function () {
return this.sort((a, b) => b - a);
};
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.
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.
var numArray = [140000, 104, 99];
numArray = numArray.sort((a,b) => a-b);
alert(numArray)
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.
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;
});
Just building on all of the above answers, they can also be done in one line like this:
var numArray = [140000, 104, 99];
// ES5
numArray = numArray.sort(function (a, b) { return a - b; });
// ES2015
numArray = numArray.sort((a, b) => a - b);
//outputs: 99, 104, 140000
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]
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));
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>
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)
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];_x000D_
for (var i = 0; i < numArray.length; i++) {_x000D_
var target = numArray[i];_x000D_
for (var j = i - 1; j >= 0 && (numArray[j] > target); j--) {_x000D_
numArray[j+1] = numArray[j];_x000D_
}_x000D_
numArray[j+1] = target_x000D_
}_x000D_
console.log(numArray);
_x000D_
Descending:
var numArray = [140000, 104, 99];_x000D_
for (var i = 0; i < numArray.length; i++) {_x000D_
var target = numArray[i];_x000D_
for (var j = i - 1; j >= 0 && (numArray[j] < target); j--) {_x000D_
numArray[j+1] = numArray[j];_x000D_
}_x000D_
numArray[j+1] = target_x000D_
}_x000D_
console.log(numArray);
_x000D_
Selection sort:
Ascending:
var numArray = [140000, 104, 99];_x000D_
for (var i = 0; i < numArray.length - 1; i++) {_x000D_
var min = i;_x000D_
for (var j = i + 1; j < numArray.length; j++) {_x000D_
if (numArray[j] < numArray[min]) {_x000D_
min = j;_x000D_
}_x000D_
}_x000D_
if (min != i) {_x000D_
var target = numArray[i];_x000D_
numArray[i] = numArray[min];_x000D_
numArray[min] = target;_x000D_
}_x000D_
}_x000D_
console.log(numArray);
_x000D_
Descending:
var numArray = [140000, 104, 99];_x000D_
for (var i = 0; i < numArray.length - 1; i++) {_x000D_
var min = i;_x000D_
for (var j = i + 1; j < numArray.length; j++) {_x000D_
if (numArray[j] > numArray[min]) {_x000D_
min = j;_x000D_
}_x000D_
}_x000D_
if (min != i) {_x000D_
var target = numArray[i];_x000D_
numArray[i] = numArray[min];_x000D_
numArray[min] = target;_x000D_
}_x000D_
}_x000D_
console.log(numArray);
_x000D_
Have fun
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);
function intArraySort(c, a) {_x000D_
function d(a, b) { return b - a }_x000D_
"string" == typeof a && a.toLowerCase();_x000D_
switch (a) {_x000D_
default: return c.sort(function(a, b) { return a - b });_x000D_
case 1:_x000D_
case "d":_x000D_
case "dc":_x000D_
case "desc":_x000D_
return c.sort(d)_x000D_
}_x000D_
};_x000D_
_x000D_
function tableExample() {_x000D_
var d = function() {_x000D_
var a = Math.floor(50 * Math.random()) + 1,_x000D_
b = [];_x000D_
for (i = 0; i <= a; i++) b.push(Math.floor(50 * Math.random()) + 1);_x000D_
return b_x000D_
},_x000D_
a = function(a) {_x000D_
var b = $("<tr/>"),_x000D_
c = $("<th/>").prependTo(b);_x000D_
$("<td/>", {_x000D_
text: intArraySort(d(), a).join(", ")_x000D_
}).appendTo(b);_x000D_
switch (a) {_x000D_
case 1:_x000D_
case "d":_x000D_
case "dc":_x000D_
case "desc":_x000D_
c.addClass("desc").text("Descending");_x000D_
break;_x000D_
default:_x000D_
c.addClass("asc").text("Ascending")_x000D_
}_x000D_
return b_x000D_
};_x000D_
return $("tbody").empty().append(a(), a(1), a(), a(1), a(), a(1), a(), a(1), a(), a(1), a(), a(1))_x000D_
};_x000D_
_x000D_
tableExample();
_x000D_
table { border-collapse: collapse; }_x000D_
th, td { border: 1px solid; padding: .25em .5em; vertical-align: top; }_x000D_
.asc { color: red; }_x000D_
.desc { color: blue }
_x000D_
<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.9.1/jquery.min.js"></script>_x000D_
<table><tbody></tbody></table>
_x000D_
Now have even more fun with a sorting method that sorts an array full of multiple items! Doesn't currently cover "associative" (aka, string keys), but it does cover about every type of value! Not only will it sort the multiple values asc
or desc
accordingly, but it will also maintain constant "position" of "groups" of values. In other words; ints are always first, then come strings, then arrays (yes, i'm making this multidimensional!), then Objects (unfiltered, element, date), & finally undefineds and nulls!
"Why?" you ask. Why not!
Now comes in 2 flavors! The first of which requires newer browsers as it uses Object.defineProperty
to add the method to the Array.protoype
Object. This allows for ease of natural use, such as: myArray.smartSort('a')
. If you need to implement for older browsers, or you simply don't like modifying native Objects, scroll down to Method Only version.
/* begin */
/* KEY NOTE! Requires EcmaScript 5.1 (not compatible with older browsers) */
;;(function(){if(Object.defineProperty&&!Array.prototype.smartSort){var h=function(a,b){if(null==a||void 0==a)return 1;if(null==b||void 0==b)return-1;var c=typeof a,e=c+typeof b;if(/^numbernumber$/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, $('<header />') ];
z.push(new Date('1/01/2011'));
z.push('three');
z.push(undefined);
z.push([ 'one', 'three', 'four' ]);
z.push([ 'one', 'three', 'five' ]);
z.push({ a: 'a', b: 'b' });
z.push({ name: 'bob', value: 'bill' });
z.push(new Date());
z.push({ john: 'jill', jack: 'june' });
z.push([ 'abc', 'def', [ 'abc', 'def', 'cba' ], [ 'cba', 'def', 'bca' ], 'cba' ]);
z.push([ 'cba', 'def', 'bca' ]);
z.push({ a: 'a', b: 'b', c: 'c' });
z.push({ a: 'a', b: 'b', c: 'd' });
Then simply sort it!
z.smartSort('asc'); // Ascending
z.smartSort('desc'); // Descending
Same as the preceding, except as just a simple method!
/* begin */
/* KEY NOTE! Method `smartSort` is appended to native `window` for global use. If you'd prefer a more local scope, simple change `window.smartSort` to `var smartSort` and place inside your class/method */
window.smartSort=function(){if(arguments){var a,b,c;for(c in arguments)arguments[c]instanceof Array&&(a=arguments[c],void 0==b&&(b="a")),"string"==typeof arguments[c]&&(b=/^a([sc]{2})?$/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
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)
_x000D_
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.
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;
}
}
Here is my sort array function in the utils library:
sortArray: function(array) {
array.sort(function(a, b) {
return a > b;
});
},
# Let's test a string array
var arr = ['bbc', 'chrome', 'aux', 'ext', 'dog'];
utils.sortArray(arr);
console.log(arr);
>>> ["aux", "bbc", "chrome", "dog", "ext", remove: function]
# Let's test a number array
var arr = [55, 22, 1425, 12, 78];
utils.sortArray(arr);
console.log(arr);
>>> [12, 22, 55, 78, 1425, remove: function]
I agree with aks, however instead of using
return a - b;
You should use
return a > b ? 1 : a < b ? -1 : 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.
const compareNumbers = (a: number, b: number): number => a - b
myArray.sort(compareNumbers)
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);
_x000D_
In the new ES6 world its much easier to do a sort
numArray.sort((a,b) => a-b);
Thats all you need :)
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))
})
_x000D_
Note that this should not be used productively,
.sort()
is better suited for this, check the other answers
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.
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}]**
Source: Stackoverflow.com