JavaScript Array.sort不适用于某些数字数组[重复]

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How to sort an array of integers correctly 14 answers
如何正确排序整数数组14个答案

I'm trying to use JavaScript's sort function on arrays of numbers and sometimes it doesn't do anything:

我正在尝试在数字数组上使用JavaScript的排序函数，有时它不会做任何事情：

var a = [200,20].sort(); // [20,200]
var b = [200,21].sort(); // [200,21]

jsfiddle

的jsfiddle

2 个解决方案

#1

Javascript sorts everything as strings (=alphabetically) by default. The string "200" is less than the string "21". To sort as numbers you have to tell it so:

默认情况下，Javascript将所有内容排序为字符串（=字母顺序）。字符串“200”小于字符串“21”。要排序为数字，您必须告诉它：

[200,21].sort(function(a,b) { return  a-b })

#2

Yep, this is the standard behaviour for "sort" because it perform "string" reordering. If you want to sort by number value you must pass a "compare" function to sort, like this:

是的，这是“排序”的标准行为，因为它执行“字符串”重新排序。如果要按数字值排序，则必须通过“比较”功能进行排序，如下所示：

[200,21].sort(function (a, b) {
  return a-b; 
})
// [21, 200]

The function must return 0 for identical value, n < 0 if a < b and n > 0 if a > b. For that reason, the difference is enough to provide sorting (assuming that you're not using huge numbers)

该函数必须为相同的值返回0，如果a b，则n> 0。因此，差异足以提供排序（假设您没有使用大数字） ，则n>

#1