How to append elements into a dictionary in Swift?

Question

I have a simple Dictionary which is defined like:

var dict : NSDictionary = [ 1 : \"abc\", 2 : \"cde\"]

Now I want to add an element into t

Answer 1

Dict.updateValue updates value for existing key from dictionary or adds new new key-value pair if key does not exists.

Example-

var caseStatusParams: [String: AnyObject] = ["userId" : UserDefault.userID ]
caseStatusParams.updateValue("Hello" as AnyObject, forKey: "otherNotes")

Result-

▿  : 2 elements
    - key : "userId"
    - value : 866
▿  : 2 elements
    - key : "otherNotes"
    - value : "Hello"

Answer 2

Swift 5 happy coding

var tempDicData = NSMutableDictionary()

for temp in answerList {
    tempDicData.setValue("your value", forKey: "your key")
}

Answer 3

SWIFT 3 - XCODE 8.1

var dictionary =  [Int:String]() 

dictionary.updateValue(value: "Hola", forKey: 1)
dictionary.updateValue(value: "Hello", forKey: 2)
dictionary.updateValue(value: "Aloha", forKey: 3)

So, your dictionary contains:

dictionary[1: Hola, 2: Hello, 3: Aloha]

Answer 4

If your dictionary is Int to String you can do simply:

dict[3] = "efg"

If you mean adding elements to the value of the dictionary a possible solution:

var dict = Dictionary<String, Array<Int>>()

dict["key"]! += [1]
dict["key"]!.append(1)
dict["key"]?.append(1)

Answer 5

For whoever reading this for swift 5.1+

  // 1. Using updateValue to update the given key or add new if doesn't exist


    var dictionary = [Int:String]()    
    dictionary.updateValue("egf", forKey: 3)



 // 2. Using a dictionary[key]

    var dictionary = [Int:String]()    
    dictionary[key] = "value"



 // 3. Using subscript and mutating append for the value

    var dictionary = [Int:[String]]()

    dictionary[key, default: ["val"]].append("value")

Answer 6

In Swift, if you are using NSDictionary, you can use setValue:

dict.setValue("value", forKey: "key")