这是因为您正在使用默认的排序算法对数字进行排序，该算法会将它们转换为字符串并按字典顺序进行排序。

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

而是通过其返回值传递定义排序顺序的函数。

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));

返回正数会将 a 移到列表末尾。

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