CODEWITHSUNDEEP
iosswiftdictionary
Vishnu
Vishnu

Reputation: 2243

Swift: Remove keys and values added during array flatMap conversion

Trying to make array of dictionaries with object, which adds keys and values during array flatMap

var parameters: [String: Any] {
var postParameters: [String: Any] = [:]
postParameters["topics"] = categories.flatMap({ toPostParameters($0) })
print(postParameters)
return postParameters
}


private func toPostParameters(_ topics: Topics) -> [String: Any] {
var params: [String: Any] = [:]
params["id"] = topics.id
params["isFound"] = topics.isFound
return params
}

when I print the postParameters value, all I get is like the following. How to remove the key and value strings appending over it.

["topicCategories": [(key: "isFound", value: true), (key: "id", value: "62ef2b63e49a"), 
(key: "id", value: "632serer269"), (key: "isFound", value: true)]]

Expected

["topicCategories": [["isFound": true, "id": "62ef2b63e49a"], 
["id": "632serer269","isFound": true]]]

Upvotes: 0

Views: 128

Answers (1)

えるまる
えるまる

Reputation: 2551

You should use map, because flatMap makes everything "flat" and you get a flat array of tuples instead of array of dictionaries.

Example:

class Topics {
    var id = 1
    var isFound = true
}

var categories = [Topics(), Topics(), Topics()]

var parameters: [String: Any] {
    var postParameters: [String: Any] = [:]
    postParameters["topics"] = categories.map({ toPostParameters($0) })
    return postParameters
}


private func toPostParameters(_ topics: Topics) -> [String: Any] {
    var params: [String: Any] = [:]
    params["id"] = topics.id
    params["isFound"] = topics.isFound
    return params
}

print(parameters)

Output:

["topics": [["id": 1, "isFound": true], ["id": 1, "isFound": true], ["isFound": true, "id": 1]]]

P.S:

Good article to understand the difference between map, compactMap and flatMap.

Upvotes: 1

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