Convert Any dictionary array to String in Swift

Question

Convert [String:Any] dictionary array to [String:String] in Swift

I have an array of dictionary <String,Any> type. Now I want to convert to string because I want to show data in textField and text field not understand Any data type.

My data like this:

var myarr = [[String:Any]]()

[
    [
        "Area" : "",
        "Good" : "-",
        "Level" : 2,
        "Link" : "<null>",
        "Photo" : "-",
        "Repair" : "-",
        "Section" : "Others"
    ],

    [
        "Area" : "",
        "Good" : "N",
        "Level" : 2,
        "Link" : "http://google.com",
        "Photo" : 1,
        "Repair" : "Y",
        "Section" : "Grounds"
    ]

]

and I want new Array Dictionary:

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

Solution 1

Here is one solution that actually gives the correct results:

let myarr = [
    [
        "Area" : "",
        "Good" : "-",
        "Level" : 2,
        "Link" : "<null>",
        "Photo" : "-",
        "Repair" : "-",
        "Section" : "Others"
    ],

    [
        "Area" : "",
        "Good" : "N",
        "Level" : 2,
        "Link" : "http://someurl",
        "Photo" : 1,
        "Repair" : "Y",
        "Section" : "Grounds"
    ]
]


var newarr = [[String:String]]()
for dict in myarr {
    var newdict = [String:String]()
    for (key, value) in dict {
        newdict[key] = "\(value)"
    }
    newarr.append(newdict)
}
print(newarr)

Output:

[["Level": "2", "Area": "", "Good": "-", "Link": "<null>", "Repair": "-", "Photo": "-", "Section": "Others"], ["Level": "2", "Area": "", "Good": "N", "Link": "http://someurl", "Repair": "Y", "Photo": "1", "Section": "Grounds"]]

Solution 2

Map is your friend, maybe something like

let stringDictionaries: [[String: String]] = myarr.map { dictionary in
    var dict: [String: String] = [:]
    dictionary.forEach { (key, value) in dict[key] = "\(value)" }
    return dict
}

Solution 3

You can create new dictionary using following code:

var newArray:[[String: String]] = []
for data in myarr {
    var dict: [String: String] = [:]
    for (key, value) in data {
        let strData = String(describing: value)
        dict[key] = strData
    }
    newArray.append(dict)
}

Comments

[Harshil Kotecha]

thank you it's work properly and not get any error in type converting

[rmaddy]

This answer is wrong. It adds an extra layer of arrays to the results.

[Harshil Kotecha]

please give another solution @rmaddy i am waiting for your solution

[John Dough]

@HarshilKotecha I updated the example using flatMap to flatten the structure to match your desired output. :)

[rmaddy]

The update is wrong too. flatmap doesn't change anything here. Please verify your answer before posting. A simple test in the playground should be done.

[John Dough]

@rmaddy I'm actually testing this in Playgrounds and the output gives me [["test1": "123"], ["test2": "345"], ["test3": "657"], ["test4": "true"]] just like OP is looking for. What do you see in Playgrounds?

[rmaddy]

Your test isn't valid. Test with a dictionary that has more than one key/value pair just like the data in the question.

[rmaddy]

This code produces the wrong result. It only works if each dictionary has one key/value pair.

[rmaddy]

Print the original array and your result array. Note how the result has a bunch of extra dictionaries.

[rmaddy]

@HarshilKotecha Not at all. It has nothing to do with memory. The result is creating a dictionary for each key/value pair found in the original dictionaries.

[Harshil Kotecha]

@JohnDough check your out put and than my code [["Section": "Grounds"]] it is true ?

[Harshil Kotecha]

let dict = stringDictionaries[0] print(dict["Section"]) check this it's not work in your output result

[John Dough]

@rmaddy thanks for staying alert - updated the example to not split into sub-dictionaries. Cheers!

[rmaddy]

Yep, that works. You can't use map on a dictionary to get a new dictionary.

[Nasser Munshi]

I've edited my code. So now you can check the output.