对Objective-c对象数组进行排序 [英] Sorting an array of Objective-c objects

问题描述

所以我有一个自定义类 Foo ，它有许多成员：

So I have a custom class Foo that has a number of members:

@interface Foo : NSObject {
    NSString *title;
    BOOL     taken;
    NSDate   *dateCreated;
}

在另一个班级我有一个 NSMutableArray 包含这些对象的列表。我非常希望根据 dateCreated 属性对此数组进行排序;我知道我可以为此编写自己的分类器（迭代数组并根据日期重新排列）但我想知道是否有一种正确的Objective-C方法来实现这一目标？

And in another class I have an NSMutableArray containing a list of these objects. I would very much like to sort this array based on the dateCreated property; I understand I could write my own sorter for this (iterate the array and rearrange based on the date) but I was wondering if there was a proper Objective-C way of achieving this?

我可以提供成员变量排序的某种排序机制会很棒。

Some sort of sorting mechanism where I can provide the member variable to sort by would be great.

在C ++中，我过去常常重载< =>运算符，这允许我按对象排序，但我有一种有趣的感觉Objective-C可能提供更好的选择？

In C++ I used to overload the < = > operators and this allowed me to sort by object, but I have a funny feeling Objective-C might offer a nicer alternative?

非常感谢

推荐答案

这很简单。

首先，在你的Foo对象中，创建一个方法

First, in your Foo object, create a method

- (NSComparisonResult) compareWithAnotherFoo:(Foo*) anotherFoo;

将返回

[[self dateCreated] compare:[anotherFoo dateCreated]];

最后，调用数组

[yourArray sortUsingSelector:@selector(compareWithAnotherFoo:)];

希望这会有所帮助，
Paul

Hope this helps, Paul

这篇关于对Objective-c对象数组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！