Instance Methodswift-algorithms 1.2.0Algorithms->Swift

minAndMax(by:)

Returns both the minimum and maximum elements in the sequence, using the given predicate as the comparison between elements.

MinMax.swift:430

func minAndMax(by areInIncreasingOrder: (Element, Element) throws -> Bool) rethrows -> (min: Element, max: Element)?

Mangled symbol

sST10AlgorithmsE9minAndMax2by7ElementQz0B0_AE3maxtSgSbAE_AEtKXE_tKF What are these?

FNV24 hash: 8FHOS

Parameters

areInIncreasingOrder: A predicate that returns true if its first argument should be ordered before its second argument; otherwise, false.

A tuple with the sequence’s minimum element, followed by its maximum element. If the sequence provides multiple qualifying minimum elements, the first equivalent element is returned; of multiple maximum elements, the last is returned. If the sequence has no elements, the method returns nil.

The predicate must be a strict weak ordering over the elements. That is, for any elements a, b, and c, the following conditions must hold:

areInIncreasingOrder(a, a) is always false. (Irreflexivity)
If areInIncreasingOrder(a, b) and areInIncreasingOrder(b, c) are both true, then areInIncreasingOrder(a, c) is also true. (Transitive comparability)
Two elements are incomparable if neither is ordered before the other according to the predicate. If a and b are incomparable, and b and c are incomparable, then a and c are also incomparable. (Transitive incomparability)

This example shows how to use the minAndMax(by:) method on a dictionary to find the key-value pair with the lowest value and the pair with the highest value.

let hues = ["Heliotrope": 296, "Coral": 16, "Aquamarine": 156]
if let extremeHues = hues.minAndMax(by: {$0.value < $1.value}) {
    print(extremeHues.min, extremeHues.max)
} else {
    print("There are no hues")
}
// Prints: "(key: "Coral", value: 16) (key: "Heliotrope", value: 296)"