按对象的属性对NSMutableArray进行排序 [英] Sorting NSMutableArray By Object's Property

问题描述

因此，对于自定义对象的 NSMutableArray 进行排序的最佳方法，这是一个相当基本的问题。

So this is a rather basic question regarding the best way to sort an NSMutableArray of custom objects.

我有一个 NSMutableArray 的自定义对象，每个对象都有一个 NSString 和 NSDate 一起去。我需要按最新的对象排序数组（所以最新的 NSDate ），我很确定我可以简单地使用 NSDate比较：NSDate 如果这是一个只有 NSDate 的数组，但由于我需要对所有对象进行排序而不仅仅是日期，我不确定我是否可以使用该方法。

I have a an NSMutableArray of custom objects, each object with an NSString and NSDate that go together. I need to sort the array by the newest object (so latest NSDate), and I'm pretty sure I could simply use NSDate compare: NSDate if this was an array of just NSDate, but since I need all objects to be sorted and not just the date, I'm not sure if I can use that method.

就伪代码而言，我需要：查看单个对象，确定当前对象的 NSDate 是数组中的下一个最大值，如果是，则移动对象，而不仅仅是日期。

In terms of pseudo-code, I need to: Look at individual object, determine if the current object's NSDate is the next biggest in the array, and if it is, move the object, not just the date.

再次，这是我甚至是犹豫不决，因为它是如此基本，但我不想写一些非常低效的方法，如果有一个预先存在的类方法基本上做我想要的，搜索对象的子属性数组并根据对象排序subproperties。

Again, this is something I was even hesitant to ask since it's so basic but I don't want to go writing some grossly inefficient method if there is a pre-existing class method that will essentially do what I want, search an array of object's sub properties and sort the objects according to the subproperties.

感谢您的帮助。

推荐答案

NSSortDescriptors s简单。使用 NSMutableArray ，您可以使用 sortUsingDescriptors：对现有数组进行排序，并使用不可变数组使用<$ c创建新数组$ c> sortedArrayUsingDescriptors：

NSSortDescriptorss make this really simple. With NSMutableArray you can sort the existing array using sortUsingDescriptors: and with immutable arrays you create a new array using sortedArrayUsingDescriptors:

//This will sort by stringProperty ascending, then dateProperty ascending
[mutable_array sortUsingDescriptors:
 @[
  [NSSortDescriptor sortDescriptorWithKey:@"stringProperty" ascending:YES],
  [NSSortDescriptor sortDescriptorWithKey:@"dateProperty" ascending:YES]
  ]];

这篇关于按对象的属性对NSMutableArray进行排序的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！