使用函数从swift字典中动态删除空值 [英] Dynamically remove null value from swift dictionary using function

问题描述

我有下面的字典代码

var dic : [String: AnyObject] = ["FirstName": "Anvar", "LastName": "Azizov", "Website": NSNull(),"About": NSNull()]

我已经使用下面的代码删除了具有空值的键

I already remove key which have null value using below code

var keys = dic.keys.array.filter({dic[$0] is NSNull})
for key in keys {
  dic.removeValueForKey(key)
}

它适用于静态字典，但我想动态地做，我想用函数完成它但是每当我把字典作为参数传递时它就像一个let意味着常量所以不能删除空键
我在下面创建代码

It works for static dictionary,But I want do it dynamically,I want to done it using function but whenever I pass dictionary as a argument it works as a let means constant so can not remove null key I make below code for that

func nullKeyRemoval(dic : [String: AnyObject]) -> [String: AnyObject]{
        var keysToRemove = dic.keys.array.filter({dic[$0] is NSNull})
        for key in keysToRemove {
            dic.removeValueForKey(key)
        }
        return dic
}

请告诉我这方面的解决方案

please tell me solution for this

推荐答案

为什么不使用全局函数（或方法），为什么不将它作为的方法字典，使用扩展名吗？

Rather than using a global function (or a method), why not making it a method of Dictionary, using an extension?

extension Dictionary {
    func nullKeyRemoval() -> Dictionary {
        var dict = self

        let keysToRemove = Array(dict.keys).filter { dict[$0] is NSNull }
        for key in keysToRemove {
            dict.removeValue(forKey: key)
        }

        return dict
    }
}

它适用于任何泛型类型（因此不限于 String，AnyObject ），您可以直接从字典中调用它本身：

It works with any generic types (so not limited to String, AnyObject), and you can invoke it directly from the dictionary itself:

var dic : [String: AnyObject] = ["FirstName": "Anvar", "LastName": "Azizov", "Website": NSNull(),"About": NSNull()]
let dicWithoutNulls = dic.nullKeyRemoval()

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