按日期排序对象数组 [英] Order array of objects by date

问题描述

例如

myArr= [
    {name:"Joe",  id:3,  date: "2012.10.12"},
    {name:"Ed",   id:43, date: "2012.02.12"},
    {name:"Mark", id:22, date: "2012.02.11"}
];

那么如何按日期对这个数组进行排序?

so how can I sort this Array by date?

这只是一个小例子，但它就像是 Array 中的 1000 个对象.我在 Internet 上搜索并找到了一些使用 sort() 函数的示例，但它在我的大数组中不起作用.

This is just small example, but it will be like 1000 Objects inside that Array. I have searched on the Internet and found some examples that used the sort() function but it doesn't work in my big Array.

推荐答案

假设日期只是按照您的代码格式化的字符串，您可以这样做:

Assuming the dates are just strings formatted as in your code, you can do this:

myArr.sort( (a,b) => a.date.localeCompare(b.date) )

sort 方法将一个函数作为参数，每次需要比较数组的两个元素时都会调用该函数.因此，要按特定字段排序，您需要传递一个函数来比较传入的两个对象的这些字段.

The sort method takes as a parameter a function that will be called every time it needs to compare two elements of the array. So to sort by a particular field, you pass a function that compares those fields of the two objects passed in.

排序比较器函数必须返回一个表示正确顺序的特殊值:-1 如果第一个参数(通常称为 a)应该在第二个(b);1 如果 b 应该在 a 之前；或 0 如果它们相等(所以顺序无关紧要).幸运的是，已经有一个方法可以比较字符串并为 sort 返回正确的值(如果你在 a 上调用它并将 b 作为参数传递): localeCompare.由于您要比较的字段是字符串，因此您只需在比较函数中的字段上调用它即可返回正确的排序值.

The sort comparator function has to return a special value indicating the correct order: -1 if the first parameter (conventionally called a) should come before the second (b); 1 if b should come before a; or 0 if they're equal (so the order doesn't matter). Fortunately, there's already a method that compares strings and returns the proper value for sort (if you call it on a and pass b as a parameter): localeCompare. Since the fields you're comparing are strings, you can just call that on the fields in your comparison function to return the proper value for the sort.

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