使用谓词的字典过滤器数组 - swift3

Posted 2023-02-23

【中文标题】使用谓词的字典过滤器数组 - swift3

【英文标题】：Array of dictionary filter using predicate - swift3

【发布时间】：2018-08-13 23:08:47

【问题描述】：

我有很多字典。

>["name": "John",
"address": 
"home": "addr1", 
"work": "add2"
,
"name": "Anu",
"address": "home": "addr1", 
"work": "add2"
]

我正在像这样将它保存到用户默认值 -

让 personData1 = ["name": "John", "address": "home": "addr1", "work": "add2"] 作为 [String : Any] 让 personData2 = ["name": "Anu", "address": "home": "addr1", "work": "add2"] as [String : Any]

var persons = [personsData, personsData1]
UserDefaults.standard.set(forKey: "persons") 

用另一种方法检索它并根据名称过滤它们。 let name = "约翰"

遇到错误

无法使用“((Any?) -> Bool)”类型的参数列表调用“过滤器”

这里是代码：-

func test () 

    let personData1 = ["name": "John", "addresses": ["home":"addr1", "work": "addr2"]] as [String : Any]
    let personData2 = ["name": "And", "addresses":  ["home":"addr1", "work": "addr2"]] as [String : Any]

    let persons = [personData1, personData2]
    (UserDefaults.standard.set(persons, forKey: "persons")

    print("Saved ----\(UserDefaults.standard.value(forKey: "persons"))")

    if let savedPersons = UserDefaults.standard.value(forKey: "persons") 
        let namePredicate = NSPredicate(format: "name like %@", name);

        var filteredArray: [[String:Any]] = savedPersons.filter  namePredicate.evaluate(with: $0) 

        print("names = \(filteredArray)")
    

如果我尝试像这样过滤 -

let filteredArray = savedBrs.filter  $0["name"] == name 

得到不同的错误 -

“任何”类型的值没有成员“过滤器”

【问题讨论】：

请在问题中包含过滤数组的代码。

【参考方案1】：

与NSPredicate

let arr = [["name":"Rego","address":["one":"peek","two":"geelo"]],["name":"pppp","address":["one":"peek","two":"geelo"]]]

let neededName = "Rego"

let pre = NSPredicate(format: "name == %@",neededName)

let result = arr.filter  pre.evaluate(with:$0)  

print(result)

没有NSPredicate

let result = arr.filter  $0["name"] as? String  == neededName 

【讨论】：

我这样声明字典 - 让 arr1: [[String:Any]] = [ ["name":"Rego","address":["one":"peek","two ":"geelo"]],["name":"pppp","address":["one":"peek","two":"geelo"]]] 我们不能使用 Any 吗？

这个声明默认给出 [[String:Any]]

如果我保存然后从用户默认值中检索此值，我会收到错误 -> 类型为“任何？”的值没有成员“过滤器”

阅读时使用 UserDefaults.standard.array(forKey: "persons")

知道了。谢谢！我像正常值一样检索它