对象到新阵列的拆分阵列基于对象的日期的年份 [英] Split array of objects into new arrays based on year of object's date

问题描述

我有对象的数组名为 objarray 。每个对象看起来是这样的：

I have an array of objects called objarray. Each object looks like this:

var object = {
    age: "45"
    coords: "-37.807997 144.705784"
    date: Sun Jul 28 2002 00:00:00 GMT+1000 (EST)
}

（日期为Date对象）

我需要每个对象推到基于日期的新数组。我想最终的结果看起来是这样的：

I need to push each object into a new array based on the date. I want the end result to look like this:

var dateGroups = [[object, object, object],[object, object], [object, object, object]];

dateGroups中的每个阵列包含相同日期的对象。

这是可以做到使用数组？ previously我产生含有一个新的对象都在 objarray 按日期（从数据生成的日期）组合的对象：

Is this possible to do with arrays? Previously I generated a new object which contained all the objarray objects grouped by date (dates generated from the data):

var alldates = {
  "1991" : [object, object, object],
  "1992" : [object, object],
  //etc...
}

上面似乎是在实践中一个奇怪的解决方案，不过，我只需要能够在今年访问对象：即 dateGroups [0] =从第一年的对象数组

The above seems like a weird solution in practice though, I only need to be able to access the objects by year: i.e. dateGroups[0] = array of objects from the first year

我如何将获取数据变得像在 dateGroups 数组？有没有更好的方式来存储这种类型的数据？

How would I get the data into something like the dateGroups array? Is there a better way to store this type of data?

推荐答案

考虑使用 Underscore.js 的groupBy 功能，其次是 sortBy

Consider using the Underscore.js groupBy function, followed by sortBy.

GROUPBY 将产生类似的 alldates 的结构，如果你调用它像这样：

groupBy will produce a structure like alldates, if you call it like so:

var alldates = _.groupBy(objarray, function(obj) {
    return obj.date.getFullYear();
});

sortBy 可用于简单的排序键，这样的：

sortBy can be used to simply sort by key, like this:

var dateGroups = _.sortBy(alldates, function(v, k) { return k; });

您也可以将二者结合起来是这样的：

You can also combine the two like this:

var dateGroups = _.chain(objarray)
                  .groupBy(function(obj) { return obj.date.getFullYear(); })
                  .sortBy(function(v, k) { return k; })
                  .value();

根据您的使用情况下，我可以看到原因使用数组的数组，数组或一个对象映射。如果你在指数往上看，肯定是使用更高版本。

Depending on your use case, I can see reasons for using an array of arrays, or an object map of arrays. If you're looking up on index, definitely use the later.

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