如何在JavaScript中对浮点数组进行排序？ [英] How to sort an array of floats in JavaScript?

问题描述

我尝试了以下示例，但现在正在使用正确的信息。

I tried below example but now working with correct information.

var fruits = [110.111, 1245.22222, 2.458, 0.001];
fruits.sort();
document.write(fruits);

结果：

0.001,110.111,1245.22222,2.458

但我想要这样的东西

0.001,2.458,110..111,1245.22222

此代码有什么问题？

推荐答案

array.sort（ [compareFunction] ） 使用可选功能作为自定义比较器

array.sort([compareFunction]) takes an optional function which works as a custom comparator

fruits.sort(function(a, b){
  return a - b;
});

如果你想降序排序

fruits.sort(function(a, b){
  return b - a;
});

---

via： MDN Array.prototype.sort docs

• 如果 compareFunction（a，b）小于0，则将a排序为低于b的索引，即a先来。


• 如果 compareFunction（a，b）返回0，则a和b相互保持不变，但是根据所有不同的元素排序。注意：ECMAscript标准不保证这种行为，因此并非所有浏览器（例如可追溯到至少2003年的Mozilla版本）都尊重这一点。


• 如果 compareFunction（ a，b）大于0，将b排序为低于a的索引。


• compareFunction（a，b）必须始终返回相同的值。如果返回不一致的结果，则排序顺序未定义



• If compareFunction(a, b) is less than 0, sort a to a lower index than b, i.e. a comes first.
• If compareFunction(a, b) returns 0, leave a and b unchanged with respect to each other, but sorted with respect to all different elements. Note: the ECMAscript standard does not guarantee this behaviour, and thus not all browsers (e.g. Mozilla versions dating back to at least 2003) respect this.
• If compareFunction(a, b) is greater than 0, sort b to a lower index than a.
• compareFunction(a, b) must always returns the same value when given a specific pair of elements a and b as its two arguments. If inconsistent results are returned then the sort order is undefined

最近，我已经一直在做一些函数式编程。对于想要以不同方式解决同一问题的人来说，我会将此部分作为另一种选择。

Lately, I've been doing some functional programming. I'll leave this section as another option for people that want to solve the same problem in different ways.

首先，我们有一些通用的实用功能。当我们想要定义更高阶 asc 和 desc 排序函数时，这些是必要的。

First we have some general utility functions. These will be necessary when we want to define our higher order asc and desc sorting functions.

const sub = x => y => y - x;
const flip = f => x => y => f (y) (x);
const uncurry = f => (x,y) => f (x) (y);
const sort = f => xs => xs.sort(uncurry (f));

现在您可以轻松定义 asc 和 desc 就 sub而言

Now you can easily define asc and desc in terms of sub

const asc = sort (flip (sub));
const desc = sort (sub);

检查出来

asc ([4,3,1,2]);  //=> [1,2,3,4]
desc ([4,3,1,2]); //=> [4,3,2,1]

您仍然可以使用<$ c $进行自定义排序c> sort（比较器）（someData）

// sort someData by `name` property in ascending order
sort ((a,b) => a.name - b.name) (someData); //=> ...

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