isStrictSubset(of:)
Returns a Boolean value that indicates whether the set is a strict subset of the given sequence.
Declaration
func isStrictSubset<S>(of possibleStrictSuperset: S) -> Bool where Element == S.Element, S : SequenceParameters
- possibleStrictSuperset:
A sequence of elements.
possibleStrictSupersetmust be finite.
Return Value
true is the set is strict subset of possibleStrictSuperset; otherwise, false.
Discussion
Set A is a strict subset of another set B if every member of A is also a member of B and B contains at least one element that is not a member of A.
let employees = ["Alicia", "Bethany", "Chris", "Diana", "Eric"]
let attendees: Set = ["Alicia", "Bethany", "Diana"]
print(attendees.isStrictSubset(of: employees))
// Prints "true"
// A set is never a strict subset of itself:
print(attendees.isStrictSubset(of: attendees))
// Prints "false"