CodeToLive

Collections in Swift

Swift provides three primary collection types: Arrays, Sets, and Dictionaries.

Arrays

var fruits = ["Apple", "Banana"]
fruits.append("Orange")
print(fruits[1])  // "Banana"

for fruit in fruits {
    print(fruit)
}

Sets

var colors: Set = ["Red", "Green", "Blue"]
colors.insert("Yellow")
print(colors.contains("Red"))  // true

Dictionaries

var capitals = ["France": "Paris", "Japan": "Tokyo"]
capitals["USA"] = "Washington"
if let capital = capitals["France"] {
    print(capital)  // "Paris"
}

Collection Operations

let numbers = [1, 2, 3, 4, 5]
let squares = numbers.map { $0 * $0 }
let evens = numbers.filter { $0 % 2 == 0 }
let sum = numbers.reduce(0, +)

Collection Comparison

Feature	Array	Set	Dictionary
Ordered	Yes	No	No
Unique Values	No	Yes	Keys only

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