Javascript数组排序功能排序不正确

Question

I have a question regarding javascript's sort() function

var arr = [23,43,54,2,3,12];
arr.sort();

it's output is [12, 2, 23, 3, 43, 54] well it should be [2, 3, 12, 23, 43, 54] ?

Answer 1

It's because you're sorting the numbers with the default sorting algorithm, which converts them to a string and sorts lexicographically.

Instead pass a function defining a sort order via its return value.

 var arr = [23,43,54,2,3,12]; console.log(arr.sort((a, b) => a - b)); 

Returning a positive number moves a toward the end of the list.

Answer 2

You have to specify a sort function

[12, 2, 23, 3, 43, 54].sort(function (a, b) { return  a - b ; } )

The javascript specification states that sort should perform lexicografic sorting, docs

Answer 3

The sorting of number is based on Unicode. Hence the oder you have is correct. Refer the link for details.

https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/sort

Answer 4

let arr = [23,43,54,2,3,12];

arr.sort((a, b) => { return a - b; // Ascending });

arr.sort((a, b) => { return b - a; // Descending });