为什么JavaScript不能排序[5,10,1]？ [英] Why can't JavaScript sort [5, 10, 1]?

问题描述

这似乎是一种简单的排序，但JavaScript却给出了错误的结果。

This seems like a simple sort, yet JavaScript is giving an incorrect result.

我做错了什么或这是一种语言怪癖？

Am I doing something wrong or is this a language quirk?

[5,10,1] .sort（）;

[5, 10, 1].sort();

[1,10,5 ]

[ 1, 10, 5 ]

推荐答案

Javascript按字母顺序排序。这意味着10低于5，因为1低于5。

Javascript sorts alphabetically. This means that "10" is lower than "5", because "1" is lower than "5".

要对数值进行排序，需要传递数值比较器像这样：

To sort numerical values you need to pass in numerical comparator like this:

function sorter(a, b) {
  if (a < b) return -1;  // any negative number works
  if (a > b) return 1;   // any positive number works
  return 0; // equal values MUST yield zero
}

[1,10, 5].sort(sorter);

或者你可以通过传递更简单的功能作弊：

Or you can cheat by passing simpler function:

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

[1, 10, 5].sort(sorter);

这个较短函数的逻辑是比较器必须返回 x> 0如果a > b ， x< 0如果< b 和零，如果a等于b 。所以万一你有

Logic behind this shorter function is that comparator must return x>0 if a > b, x<0 if a < b and zero if a is equal to b. So in case you have

a=1 b=5
a-b will yield negative(-4) number meaning b is larger than a

a=5 b=1
a-b will yield positive number(4) meaning a is larger than b

a=3 b=3
a-b will yield 0 meaning they are equal

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