CODEWITHSUNDEEP
iosiphonehigher-order-functionsswift5
karthikeyan
karthikeyan

Reputation: 3898

Map value in particular key in array of dictionary

Map value the particular key wherever presents in array of dictionary and replace it in same array.

We need to update pan_card key 0 to 1, in occurence of array of dictionary.

let keyToUpdate = "pan_card"
var arrayOfDictionary = [[String:Any]]()
var firstDict = [String:Any]()
firstDict["passport"] = 0
firstDict["ration_card"] = 0
firstDict["pan_card"] = 0

var arrayDict = [String : Any]()
arrayDict["currentObject"] = firstDict
arrayDict["title"] = "Documents list"

var secondDict = [String:Any]()
secondDict["dl"] = 0
secondDict["voter"] = 0
secondDict["pan_card"] = 0

//let dic = secondDict.filter({ $0.value as! NSNumber != 0})
//secondDict = dic
//print(secondDict)
//let dictionary = ["foo": 1, "bar": 2, "baz": 5]
//
//let newDictionary = dictionary.mapValues { value in
//    return value - value
//}
//print(dictionary)
//print(newDictionary)
var arrayDict2 = [String : Any]()
arrayDict2["currentObject"] = secondDict
arrayDict2["title"] = "Second Documents list"


arrayOfDictionary.append(arrayDict)
arrayOfDictionary.append(arrayDict2)
//print(arrayOfDictionary)



    for (index, dictionary) in arrayOfDictionary.enumerated() {
    let dict = dictionary
    let newDictionary = (dict["currentObject"] as![String:Any]).mapValues { value in
            return 1
        }
    arrayOfDictionary[index] = newDictionary
}
print(arrayOfDictionary)

This code updating every key in currentObject

and tried this as well, but it adding new key 

for (index, dictionary) in arrayOfDictionary.enumerated() {
    var dict = dictionary
//    let newDictionary = (dict["currentObject"] as![String:Any]).mapValues { value  in
//            return 1
//        }
    var newDictionary = [String: Any]()
    for (key, value) in dict["currentObject"] as![String:Any] {
        dict[keyToUpdate, default: value] = 1
    }
        arrayOfDictionary[index] = dict
}
print(arrayOfDictionary)

I need output like below

Original value

[["currentObject": ["passport": 0, "pan_card": 0, "ration_card": 0], "title": "Documents list"], ["currentObject": ["pan_card": 0, "dl": 0, "voter": 0], "title": "Second Documents list"]]

after update 

[["currentObject": ["passport": 0, "pan_card": 1, "ration_card": 0], "title": "Documents list"], ["currentObject": ["pan_card": 1, "dl": 0, "voter": 0], "title": "Second Documents list"]]

Referred Document Link

We knows manually iterating and updating values, we wanted to done with higher order function.

Upvotes: 0

Views: 379

Answers (1)

Joakim Danielson
Joakim Danielson

Reputation: 52118

Using a recursive method that performs the update

func update(key:String, in dict: [String:Any], with value: Any) -> [String:Any] {
    var out = [String:Any]()
    if let _ = dict[key] {
        out = dict
        out[key] = value
    } else {
        dict.forEach {
            if let innerDict = $0.value as? [String:Any] {
                out[$0.key] = update(key: key, in: innerDict, with: value)
            } else {
                out[$0.key] = $0.value
            }
        }
    }
     return out
}

we can use a simple map call 

var original = [["currentObject": ["passport": 0, "pan_card": 0, "ration_card": 0], "title": "Documents list"], ["currentObject": ["pan_card": 0, "dl": 0, "voter": 0], "title": "Second Documents list"]]
let result = original.map{ update(key: "pan_card", in: $0, with: 1)}

The update function was based on this answer

Upvotes: 1

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