How to Append Elements into a Dictionary in Swift

How to append elements into a dictionary in Swift?

You're using NSDictionary. Unless you explicitly need it to be that type for some reason, I recommend using a Swift dictionary.

You can pass a Swift dictionary to any function expecting NSDictionary without any extra work, because Dictionary<> and NSDictionary seamlessly bridge to each other. The advantage of the native Swift way is that the dictionary uses generic types, so if you define it with Int as the key and String as the value, you cannot mistakenly use keys and values of different types. (The compiler checks the types on your behalf.)

Based on what I see in your code, your dictionary uses Int as the key and String as the value. To create an instance and add an item at a later time you can use this code:

var dict = [1: "abc", 2: "cde"] // dict is of type Dictionary<Int, String>
dict[3] = "efg"

If you later need to assign it to a variable of NSDictionary type, just do an explicit cast:

let nsDict = dict as! NSDictionary

And, as mentioned earlier, if you want to pass it to a function expecting NSDictionary, pass it as-is without any cast or conversion.

How to append elements into dictionary at specific index swift

You can't do this with Dictionary as it has no sorting criteria , only you can add element for a key , this way can be in Array only

How do you add a Dictionary of items into another Dictionary

You can define += operator for Dictionary, e.g.,

func += <K, V> (left: inout [K:V], right: [K:V]) { 
    for (k, v) in right { 
        left[k] = v
    } 
}

how to append new element to key value pair in swift

The issue there is that KeyValuePairs unlike a regular dictionary, doesn't conform to Hashable. You cannot assign through subscript. You may have duplicated key/value pairs. It conforms to RandomAccessCollection so through subscript you can only get but not set a value.

keyValuePair = [element.tabName: issueFieldArray] works because KeyValuePairs conform to ExpressibleByDictionaryLiteral but you can NOT append a new key value pair because it doesn't conform to RangeReplaceableCollection. In other words you need to add all key value pairs when initialising your collection.

How do I add values in dictionary?

Just take an array of dictionary

var arrOfDict = [[String :AnyObject]]()
var dictToSaveNotest = [String :AnyObject]()

@IBAction func addItem(_ sender: Any)
{
  dictToSaveNotest .updateValue(textField.text! as AnyObject, forKey: "title")
  dictToSaveNotest .updateValue(NotesField.text! as AnyObject, forKey: "notesField")
  arrOfDict.append(dictToSaveNotest)
}

And just populate it in the tableView Data source method By just make two outlet in the tableViewCell Class titleLable and notesLabel

 func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
 var cell = self.tableView.dequeueReusableCellWithIdentifier("cell") as! yourTableViewCell

        cell.titleLabel.text = arrayOfDict[indexPath.row]["title"] as! String!
        cell.notesLabel.text = arrayOfDict[indexPath.row]["notesField"] as! String!

        return cell
    }

Note : I have not tested it on the code , but hope it will work definitely.
All the best .

Appending dictionary values to array in Swift

You should only sort the keys and then use that array to select from the dictionary and append your sortedValues array. I made the sortedKeys into a local variable

func sortItems() {
    let sortedKeys = self.dictionary.keys.sorted(by: >)

    for key in sortedKeys {
        if let obj = dictionary[key] {
            self.sortedValues.append(obj)
        }
    }
}

I don't know if this will make a difference in regard to the crash but another way is to let the function return an array

func sortItems() -> [Object] {
    let sortedKeys = self.dictionary.keys.sorted(by: >)
    var result: [Object]()

    for key in sortedKeys {
        if let obj = dictionary[key] {
            result.append(obj)
        }
    }
    return result
}

and then call it

self.sortedValues = sortItems()

How to add another dictionary entry to an existing dictionary to form a new dictionary (i.e. not append)

There is a built-in merging(_:uniquingKeysWith:) function on Dictionary that does exactly what you need.

let dictionary = [1:1]
let otherDictionary = [1:2, 2:3]
// This will take the values from `otherDictionary` if the same key exists in both
// You can use `$0` if you want to take the value from `dictionary` instead
let mergedDict = dictionary.merging(otherDictionary, uniquingKeysWith: { $1 })

If you want, you can easily define a + operator for Dictionary that uses the above function.

extension Dictionary {
    static func + (lhs: Self, rhs: Self) -> Self {
        lhs.merging(rhs, uniquingKeysWith: { $1 })
    }
}

let addedDict = dictionary + otherDictionary

Append to array in [String: Any] dictionary structure

The type of data[Items] isn't Array but actually Array<[String: Any]>.

You could probably squeeze this into fewer steps, but I prefer the clarity of multiple steps:

var data: [String: Any] = [
    "key1": "example value 1",
    "key2": "example value 2",
    "items": []
]

for index in 1...3 {

    let item: [String: Any] = [
        "key": "new value"
    ]

    // get existing items, or create new array if doesn't exist
    var existingItems = data["items"] as? [[String: Any]] ?? [[String: Any]]()

    // append the item
    existingItems.append(item)

    // replace back into `data`
    data["items"] = existingItems
}

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