Instance Property

first

The first element of the collection.

Declaration

var first: (key: Key, value: Value)? { get }

Discussion

If the collection is empty, the value of this property is nil.

let numbers = [10, 20, 30, 40, 50]
if let firstNumber = numbers.first {
    print(firstNumber)
}
// Prints "10"

See Also

Accessing Keys and Values

subscript(Key) -> Value?

Accesses the value associated with the given key for reading and writing.

subscript(Key, default: () -> Value) -> Value

Accesses the value with the given key. If the dictionary doesn’t contain the given key, accesses the provided default value as if the key and default value existed in the dictionary.

func index(forKey: Key) -> Dictionary<Key, Value>.Index?

Returns the index for the given key.

subscript(Dictionary<Key, Value>.Index) -> Dictionary<Key, Value>.Element

Accesses the key-value pair at the specified position.

var keys: Dictionary<Key, Value>.Keys

A collection containing just the keys of the dictionary.

var values: Dictionary<Key, Value>.Values

A collection containing just the values of the dictionary.

func randomElement() -> (key: Key, value: Value)?

Returns a random element of the collection.

func randomElement<T>(using: inout T) -> (key: Key, value: Value)?

Returns a random element of the collection, using the given generator as a source for randomness.