Returns a Boolean value that indicates whether this set is a strict subset of the given set.
SDKs
- iOS 7.0+
- macOS 10.9+
- Mac Catalyst 13.0+
- tvOS 9.0+
- watchOS 2.0+
- Xcode 8.0+
Framework
- Foundation
Declaration
Parameters
otherA set of the same type as the current set.
Return Value
true if the set is a strict subset of other; 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: Set = ["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"