Swift Dictionary randomElement()

// Create a dictionary with three elements
var information = ["Charlie": 54, "Harvey": 38, "Donna": 34]

// get random element using randomElement()
var result = information.randomElement()!

// print updated dictionary
print(result)

// Output: (key: "Harvey", value: 38)

randomElement() Syntax

The syntax of the randomElement() method is:

dictionary.randomElement()

Here, dictionary is an object of the Dictionary class.

randomElement() Parameters

The randomElement() method doesn't take any parameter.

randomElement() Return Value

• The randomElement() method returns a random element from the dictionary.

Note: The randomElement() method returns an optional value, so we need to unwrap it. There are different techniques to unwrap optionals. To learn more about optionals, visit Swift Optionals.

Example 1: Swift randomElement()

// Create a dictionary with three elements
var information = ["Carlos": 1999, "Judy": 1992, "Nelson": 1987]

// get random element without unwrapping optionals
print(information.randomElement())

// get random element after unwrapping optionals
print(information.randomElement()!)

Output

Optional((key: "Carlos", value: 1999))
(key: "Carlos", value: 1999)

In the above example, we have created a dictionary named information. Notice the following:

• information.randomElement() - since we have not unwrapped the optional, the method returns Optional((key: "Carlos", value: 1999))
• information.randomElement()! - since we have used ! to force unwrap the optional, the method returns (key: "Carlos", value: 1999)

To learn more about forced unwrapping, visit Optional Forced Unwrapping.

Example 2: Using ?? Operator With randomElement()

// create a dictionary with two elements
var info1 = ["Uikit": 2001, "Swiftui": 2019]

// return random element from info1
print(info1.randomElement() ?? "Empty")

// create empty dictionary
var info2 = [String:Int]()

// return random element from info2
print(info2.randomElement() ?? "Empty")

Output

(key: "Swiftui", value: 2019)
Empty

Here, the nil-coalescing operator ?? unwraps the optional dictionary info1 and info2 if they contain a value else it returns the default value "Empty".