Swift Set

// Initializing an empty set
var emptyIntSet = Set<Int>()

// Initializing with an array literal using explicit type annotation
var stringSet: Set<String> = ["Apple", "Banana", "Cherry"]

// Initializing with type inference (type is inferred as Set<Double>)
var doubleSet: Set = [1.5, 2.0, 3.14]

let count = stringSet.count          // Returns the number of elements
let isEmpty = stringSet.isEmpty      // Returns a Boolean indicating if count == 0

// Constant-time O(1) membership check
let containsApple = stringSet.contains("Apple") 

// Insertion returns a tuple: (inserted: Bool, memberAfterInsert: Element)
let insertResult = stringSet.insert("Date")
// insertResult.inserted is true if "Date" was not already in the set

// Removal returns an Optional containing the removed element, or nil if not found
let removedElement = stringSet.remove("Banana")

// Removes all elements, optionally keeping the allocated capacity
stringSet.removeAll(keepingCapacity: true)

let setA: Set = [1, 2, 3, 4]
let setB: Set = [3, 4, 5, 6]

// Union: Elements in either set
let unionSet = setA.union(setB) 
// Result: [1, 2, 3, 4, 5, 6] (unordered)

// Intersection: Elements common to both sets
let intersectionSet = setA.intersection(setB) 
// Result: [3, 4]

// Subtracting: Elements in setA that are not in setB
let differenceSet = setA.subtracting(setB) 
// Result: [1, 2]

// Symmetric Difference: Elements in either set, but not both
let symmetricDiffSet = setA.symmetricDifference(setB) 
// Result: [1, 2, 5, 6]

let setC: Set = [1, 2]

// Subset: All elements of setC are contained in setA
let isSubset = setC.isSubset(of: setA)               // true

// Superset: setA contains all elements of setC
let isSuperset = setA.isSuperset(of: setC)           // true

// Strict Subset/Superset: Subset/Superset, but the sets are not equal
let isStrictSubset = setC.isStrictSubset(of: setA)   // true

// Disjoint: The sets have no elements in common
let isDisjoint = setC.isDisjoint(with: setB)         // true

// Unordered iteration
for number in setA {
    print(number)
}

// Ordered iteration (returns an Array)
for number in setA.sorted() {
    print(number)
}