Question

我有一个数组，该数组在包含created_at和值的每一行中包含一个哈希。如何从数组中获取值字段的最小值和最大值？

该数组称为-import * as express from "express"; test("foo", () => { jest.mock("express", () => { Router: () => jest.fn() }); // ...test stuff });

和

channels_counts_for_history_graph

给我最大日期而不是最大值吗？

channels_counts_for_history_graph.max[1]

任何帮助表示赞赏。

谢谢

Answer 1

我建议使用Enumerable#minmax_by来通过一个方法调用来获得最小值和：

array = [['Sun, 30 Dec 2018 15:03:55 UTC +00:00', 4305],['Sun, 30 Dec 2018 15:05:42 UTC +00:00', 4305],['Mon, 31 Dec 2018 09:24:06 UTC +00:00', 4306],['Sat, 05 Jan 2019 09:04:50 UTC +00:00', 4308],['Tue, 01 Jan 2019 11:26:04 UTC +00:00', 4306],['Wed, 02 Jan 2019 17:24:19 UTC +00:00', 4305]]

array.minmax_by(&:last)
#=> [["Sun, 30 Dec 2018 15:03:55 UTC +00:00", 4305], ["Sat, 05 Jan 2019 09:04:50 UTC +00:00", 4308]]

Answer 2

我可能想这就是您要的：

 [{ created_at: Date.new(2017, 1, 1) }, { created_at: Date.new(2019, 1, 1) }, { created_at: Date.new(2018, 1, 1) }]
   .minmax_by { |value| value[:created_at] }

Answer 3

默认情况下，对数组进行排序时，将首先按第一个元素进行排序。

您可以出于排序目的反转数组。

channel_counts_for_history_graph.map(&:reverse).max[0]

从此哈希数组中获取最小值和最大值

3 个答案: