Instance Method インスタンスメソッド

update(with:)

Inserts the given element into the set unconditionally.

Declaration 宣言 

mutating func update(with newMember: AccessibilityTraits) -> AccessibilityTraits?

Return Value 戻り値

For ordinary sets, an element equal to newMember if the set already contained such a member; otherwise, nil. In some cases, the returned element may be distinguishable from newMember by identity comparison or some other means.

Parameters パラメータ

newMember

An element to insert into the set.

Discussion 議論

If an element equal to newMember is already contained in the set, newMember replaces the existing element. In this example, an existing element is inserted into classDays, a set of days of the week.


enum DayOfTheWeek: Int {
    case sunday, monday, tuesday, wednesday, thursday,
        friday, saturday
}


var classDays: Set<DayOfTheWeek> = [.monday, .wednesday, .friday]
print(classDays.update(with: .monday))
// Prints "Optional(.monday)"