[Swift] Set

Set

- Unordered Collection

- Unique Value

- Set Literal = Array Literal

//let fruitsArr = ["Apple", "Orange", "Melon"]
//let numbersArr = [1, 2, 3, 3, 3]
//let emptyArr = [String]()

let fruitsSet: Set = ["Apple", "Orange", "Melon"]
let numbers: Set = [1, 2, 3, 3, 3]
let emptySet = Set()

※ Number of Element

fruitsSet.count

if !fruitsSet.isEmpty {
    print("\(fruitsSet.count) element(s)")
} else {
    print("empty set")
}

※ Searching

if fruitsSet.contains("Apple") {
  
}

let productSet: Set = ["iPhone", "iPad", "Mac Pro", "iPad Pro", "Macbook Pro"]
let filteredSet = productSet.filter { (element) -> Bool in
  return element.hasPrefix("i")
}

filteredSet

※ Add a New Element

//[1,2,3].append(1)
//[1,2,3].insert(2, at: 0)

var set: Set = []
set.insert("Apple")
set

var result = set.insert("Orange")
result
set

result = set.insert("Orange")
result
set

※ Remove an Element

set = ["Apple", "Orange", "Melon"]

if let removed = set.remove("Apple") {
    print("\(removed) has been removed!")
}

set

set.removeAll(keepingCapacity: true)

※ Compare two sets

var favoriteFruits = Set(["Apple", "Orange", "Melon"])
//var tropicalFruits = Set(["Banana", "Papaya", "Kiwi", "Pineapple"])
var tropicalFruits = Set(["Orange", "Melon", "Apple"])

if favoriteFruits == tropicalFruits {
    print("favoriteFruits == tropicalFruits")
} else {
    print("favoriteFruits != tropicalFruits")
}

if favoriteFruits.elementsEqual(tropicalFruits) {
    print("favoriteFruits == tropicalFruits")
} else {
    print("favoriteFruits != tropicalFruits")
}

var tropicalFruits1 = Set(["Apple", "Orange", "Melon"])
var tropicalFruits2 = Set(["Orange", "Melon", "Apple"])

※ Subset & Superset

tropicalFruits = Set(["Banana", "Papaya", "Kiwi", "Pineapple"])
let yellowFruits = Set(["Banana"])
//let yellowFruits = Set(["Banana", "Papaya", "Kiwi", "Pineapple"])

if yellowFruits.isSubset(of: tropicalFruits) {
    print("yellowFruits ⊂ tropicalFruits")
} else {
    print("yellowFruits ⊄ tropicalFruits")
}

if yellowFruits.isStrictSubset(of: tropicalFruits) {
    print("yellowFruits ⊂ tropicalFruits")
} else {
    print("yellowFruits ⊄ tropicalFruits")
}

if tropicalFruits.isSuperset(of: yellowFruits) {
    print("tropicalFruits ⊃ yellowFruits")
} else {
    print("tropicalFruits ⊅ yellowFruits")
}

if tropicalFruits.isStrictSuperset(of: yellowFruits) {
    print("tropicalFruits ⊃ yellowFruits")
} else {
    print("tropicalFruits ⊅ yellowFruits")
}

※ Fundamental Set Operations

- intersection

favoriteFruits = Set(["Apple", "Orange", "Melon", "Kiwi"])
tropicalFruits = Set(["Banana", "Papaya", "Kiwi", "Pineapple"])

if favoriteFruits.isDisjoint(with: tropicalFruits) {
    print("favoriteFruits ∩ tropicalFruits = ∅")
} else {
    print("favoriteFruits ∩ tropicalFruits")
}

let commonSet = favoriteFruits.intersection(tropicalFruits)
commonSet

tropicalFruits.formIntersection(favoriteFruits)
tropicalFruits

- union

var unionSet = favoriteFruits.union(tropicalFruits)
unionSet

unionSet = Set(favoriteFruits)
unionSet.formUnion(tropicalFruits)
unionSet

- subtracting

let uncommonSet = favoriteFruits.subtracting(tropicalFruits)
uncommonSet

favoriteFruits.subtract(tropicalFruits)
favoriteFruits

- symmetricDifference

let exclusiveSet = favoriteFruits.symmetricDifference(tropicalFruits)
exclusiveSet

favoriteFruits.formSymmetricDifference(tropicalFruits)
favoriteFruits