Swift:使用数组作为值过滤字典 [英] Swift: Filter a Dictionary with Array as Value

问题描述

我是Swift编程的新手.对于我的特定项目，我试图用一些用户输入来过滤字典，并且字典的值由一个数组组成.

I'm new to Swift programming. For my particular project, I'm trying to filter a dictionary with some user input, and the dictionary's value consists of an array.

这是一些示例代码，以及我要完成的工作:

Here is some sample code, and what I'm trying to accomplish:

var dictionary = ["a": ["aberration", "abc"], "b" : ["babel", "bereft"]]

var filteredDictionary = [String: [String]]()

var searchText = "aberration"

//getting the first letter of string
var firstLetter = searchText[searchText.startIndex]

使用这个特定的searchText，我试图获得:

With this particular searchText, I'm trying to get:

filteredDictionary = ["a": ["aberration"]]

我希望字典以第一个字母作为键返回，并与searchText匹配的值返回.抱歉，我不清楚.

I want the dictionary to return with the first letter as its key, and the values with what searchText matches up with. Sorry if it I wasn't clear.

这是我尝试过的一些代码，但是显然，我无法使它正常工作:

Here is some code I have tried, but obviously, I can't get it to work:

filteredDictionary = dictionary.filter{$0.key == firstLetter && for element in $0.value { element.hasPrefix(searchText) }}

任何帮助将不胜感激.谢谢.

Any help would be appreciated. Thanks.

推荐答案

这是一种解决方案，可以根据搜索结果映射值，然后过滤出空结果.

Here's a solution that maps the values based on the search and then filters out the empty results.

var dictionary = ["a": ["aberration", "abc"], "b" : ["babel", "bereft"]]
var searchText = "aberration"
let filteredDictionary = dictionary.mapValues { $0.filter { $0.hasPrefix(searchText) } }.filter { !$0.value.isEmpty }
print(filteredDictionary)

输出:

["a":[像差"]]

["a": ["aberration"]]

这篇关于Swift:使用数组作为值过滤字典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！