JavaScript sort() Method

Complete Array Object Reference

Definition and Usage

The sort() method is used to sort the elements of an array.

Syntax

arrayObject.sort(sortby)

Tips and Notes

Note: The sort() method will sort the elements alphabetically by default. However, this means that numbers will not be sorted correctly (40 comes before 5). To sort numbers, you must create a function that compare numbers.

Note: After using the sort() method, the array is changed.

Example 1

In this example we will create an array and sort it alphabetically:

<script type="text/javascript">

var arr = new Array(6);
arr[0] = "Jani";
arr[1] = "Hege";
arr[2] = "Stale";
arr[3] = "Kai Jim";
arr[4] = "Borge";
arr[5] = "Tove";

document.write(arr + "<br />");
document.write(arr.sort());

</script>

The output of the code above will be:

Jani,Hege,Stale,Kai Jim,Borge,Tove
Borge,Hege,Jani,Kai Jim,Stale,Tove

Example 2

In this example we will create an array containing numbers and sort it:

<script type="text/javascript">

var arr = new Array(6);
arr[0] = "10";
arr[1] = "5";
arr[2] = "40";
arr[3] = "25";
arr[4] = "1000";
arr[5] = "1";

document.write(arr + "<br />");
document.write(arr.sort());

</script>

The output of the code above will be:

10,5,40,25,1000,1
1,10,1000,25,40,5

Note that the numbers above are NOT sorted correctly (by numeric value). To solve this problem, we must add a function that handles this problem:

<script type="text/javascript">

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

var arr = new Array(6);
arr[0] = "10";
arr[1] = "5";
arr[2] = "40";
arr[3] = "25";
arr[4] = "1000";
arr[5] = "1";

document.write(arr + "<br />");
document.write(arr.sort(sortNumber));

</script>

The output of the code above will be:

10,5,40,25,1000,1
1,5,10,25,40,1000

Try-It-Yourself Demos

sort() alphabetically
How to use sort() to sort an array alphabetically.

sort() by number
How to use sort() to sort an array by number.

Complete Array Object Reference

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