How do I create a dictionary with arrays as the object?

Question

class MyClass {

    var lists = Dictionary<String, Any>()

    init(){
        lists["lobby"] = [Int]()
        lists["events"] = [Int]()
        lists["missed"] = [Int]()
    }


    func isInsideList(id: Int, whichList: String) -> Bool{ //whichList could be "lobby", "events", or "missed"
        //check if "id" is inside the specified array?
       if let theList = lists[whichList] as? Array {  //this throws an error
           if theList.contains(id) ......
       }
    }
}

How can I achieve this?

Indeed... the whole point of the if-let-as? is to attempt something that might fail and not throw an error if it does... — Nicolas Miari
– Nicolas Miari, Commented Jan 25, 2016 at 6:38
Also, perhaps you would like to define your method as func isInsideList(id: Int, whichList: String) -> Bool — Nicolas Miari
– Nicolas Miari, Commented Jan 25, 2016 at 6:38

vikash1307 · Accepted Answer · 2016-01-25 06:54:31Z

1

func isInsideList(id: Int, whichList: String) -> Bool {

if let theList = lists[whichList] as? [Int] {  

  if theList.contains(id) {

        return true
    }
}

return false

}

answered Jan 25, 2016 at 6:54

vikash1307

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2 Comments

TIMEX Over a year ago

How do I append to this list? It says "Any?" has no member "append"

vikash1307 Over a year ago

var str = "Hello, playground" var lists = [String : AnyObject]() lists["lobby"] = [1,3,4,5,6] lists["events"] = [3,6,78,8] lists["missed"] = [0,9,9,9,9,9] func isInsideList(id: Int, whichList: String) -> Bool{ //whichList could be "lobby", "events", or "missed" //check if "id" is inside the specified array? if let theList = lists[whichList] as? [Int] { //this throws an error if theList.contains(id) { return true } } return false } isInsideList(6, whichList: "lobby")

dsapalo · Accepted Answer · 2016-01-25 08:09:10Z

If you can opt to typecast the dictionary, do so, like the following:

var lists = Dictionary<String, [Int]>()

lists["lobby"] = [Int]()
lists["events"] = [Int]()
lists["missed"] = [Int]()


func isInsideList(id: Int, whichList: String) -> Bool{
    //whichList could be "lobby", "events", or "missed"
    //check if "id" is inside the specified array?
    if let theList = lists[whichList] {
        for (var i = 0; i < theList.count; i++){
            if (id == theList[i]){
                return true
            }
        }
    }
    return false
}

However, if you require that your dictionary contains an array of possibly various kinds of objects, then you can do the following:

var anyList = Dictionary<String, Array<AnyObject?>>()

anyList["lobby"] = [String]()
anyList["events"] = [String]()
anyList["missed"] = [String]()

func isInsideAnyList(id: Int, whichList: String) -> Bool{
    // Attempt to get the list, if it exists
    if let theList = anyList[whichList] {

        // Loop through each element of the list
        for (var i = 0; i < theList.count; i++){
            // Perform type cast checks on each element, not on the array itself
            if (String(id) == theList[i] as? String){
                return true
            }
        }
    }
    return false
}

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