Question

我是swift的新手，我有一个新项目。我正在尝试搜索功能。我有一个字典数组，包含firstName和lastName作为键，我需要根据包含搜索字符串的firstName过滤掉人物

let nameList : [Dictionary<String,String>] = 
[["firstName" : "John Sam","lastName" : "Smith"],
["firstName" : "Johnny","lastName" : "Smith"],
["firstName" : "Albert","lastName" : "Smith"],
["firstName" : "Alby","lastName" : "Wright"],
["firstName" : "Smith","lastName" : "Green"]]

在目标C中，我可以轻松地使用

[NSPredicate predicatewithformat:"firstName contains[c] %@",searchText]

我也明白同样的谓词可以在Swift上完成。但我正在寻找一个等效的Swift，这样我就可以获得如何使用map和filter。任何帮助表示赞赏

Answer 1

使用"CONTAINS[c]"选项rangeOfString()可以实现与谓词运算符.CaseInsensitiveSearch对应的搜索：

let searchText = "MITH"

let filtered = nameList.filter {
    return $0["firstName"]?.rangeOfString(searchText, options: .CaseInsensitiveSearch) != nil
}

// Result: [[firstName: Smith, lastName: Green]]

斯威夫特3：

let filtered = nameList.filter {
    return $0["firstName"]?.range(of: searchText, options: .caseInsensitive) != nil
}

Answer 2

您可以通过先定义要过滤的函数进行过滤，或者只在过滤器中包含过滤器。这里有一段摘录，您可以将其粘贴到演示两种选项的游乐场中：

let nameList : [Dictionary<String,String>] =
[["firstName" : "John Sam","lastName" : "Smith"],
    ["firstName" : "Johnny","lastName" : "Smith"],
    ["firstName" : "Albert","lastName" : "Smith"],
    ["firstName" : "Alby","lastName" : "Wright"],
    ["firstName" : "Smith","lastName" : "Green"]]

func fn (x: Dictionary<String,String>) -> Bool {
    return x["firstName"] == "Johnny"
}

nameList.filter(fn)

var r = nameList.filter({$0["firstName"] == "Johnny"})

r

var s = nameList.filter({$0["lastName"] == "Smith"})

s

您还可以过滤过滤器的结果以搜索名字和姓氏，例如

var result = (nameList.filter({$0["lastName"] == "Smith"})).filter({$0["firstName"] == "Johnny"})

另请参阅：http://locomoviles.com/ios-tutorials/filtering-swift-array-dictionaries-object-property/

Answer 3

请尝试以下方式。

我已通过constant value您需要在dynamic value处传递someString variable。

let someString = "Alby"
        var arr:NSArray =
            [["firstName" : "John Sam","lastName" : "Smith"],
            ["firstName" : "Johnny","lastName" : "Smith"],
            ["firstName" : "Albert","lastName" : "Smith"],
            ["firstName" : "Alby","lastName" : "Wright"],
            ["firstName" : "Smith","lastName" : "Green"]]


        var pre:NSPredicate = NSPredicate(format: "firstName CONTAINS[c] %@", someString)!
        var result:NSArray = arr.filteredArrayUsingPredicate(pre)

        print(result)

Answer 4

尝试，

let searchText = "John Sam"

func isMatch (nameDictionary: Dictionary<String, String>) -> Bool {
    if(nameDictionary["firstName"] == searchText) {
        return true
    }
    else {
        return false
    }

}

let results = nameList.filter(isMatch)

您可以自由使用关闭。

let searchText = "John Sam"

let results = nameList.filter {
    nameDictionary in
    nameDictionary["firstName"] == searchText
}

或，

let searchText = "John Sam"
    let results = nameList.filter {
        $0["firstName"] == searchText
    }

使用Swift搜索基于搜索文本的数组

4 个答案: