This content originally appeared on flaviocopes.com and was authored by flaviocopes.com
This tutorial belongs to the Swift series
Sets are used to create collections of non-repeated items.
While an array can contain many times the same item, you only have unique items in a set.
You can declare a set of Int values in this way:
let set: Set<Int> = [1, 2, 3]or you can initialize it from an array:
let set = Set([1, 2, 3])Add items to the set using insert():
var set = Set([1, 2, 3])
set.insert(17)Unlike arrays, there is no order or position in a set. Items are retrieved and inserted randomly.
The way to print the content of a set ordered is to transform it into an array using the sorted() method:
var set = Set([2, 1, 3])
let orderedList = set.sorted()To check if a set contains an element, use the contains() method:
var set = Set([1, 2, 3])
set.contains(2) //trueTo get the number of items in the set, use the count property:
let set = Set([1, 2, 3])
set.count //3If a set is empty, its isEmpty property is true.
let set = Set([1, 2, 3])
set.isEmpty //falseTo remove one item from the array, use remove() passing the value of the element:
var set = Set([1, 2, 3])
set.remove(1)
//set is [2, 3]To remove all items from the set, you can use removeAll():
set.removeAll()Sets, like arrays, are passed by value, which means if you pass an array to a function, or return it from a function, the set is copied.
Sets are great to perform set math operations like intersection, union, subtracting, and more.
These methods help with this:
intersection(_:)symmetricDifference(_:)union(_:)subtracting(_:)isSubset(of:)isSuperset(of:)isStrictSubset(of:)isStrictSuperset(of:)isDisjoint(with:)
Sets are collections, and they can be iterated over in loops.
This content originally appeared on flaviocopes.com and was authored by flaviocopes.com
flaviocopes.com | Sciencx (2021-06-04T05:00:00+00:00) Swift Sets. Retrieved from https://www.scien.cx/2021/06/04/swift-sets/
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