Swift Operators

Types of Swift Operators

let sum = 10 + 5    // 15
let product = 4 * 3  // 12

let isEqual = 5 == 5  // true
let isGreater = 10 > 3 // true

let both = true && false // false
let either = true || false // true

var count = 5
count += 3  // count is now 8

🔹 Assignment Operators

The assignment operator (=) assigns a value to a variable:

// Basic assignment
var name = "Swift"
var age = 25

// Compound assignment operators
var score = 100
score += 10    // score = score + 10 (now 110)
score -= 5     // score = score - 5 (now 105)
score *= 2     // score = score * 2 (now 210)
score /= 3     // score = score / 3 (now 70)

// String assignment
var message = "Hello"
message += " World"  // message is now "Hello World"

print("Final score: \(score)")
print("Message: \(message)")

🔹 Unary Operators

Unary operators work on a single value:

// Unary minus (negation)
let positiveNumber = 42
let negativeNumber = -positiveNumber  // -42

// Unary plus (rarely used)
let explicitPositive = +42

// Logical NOT operator
let isTrue = true
let isFalse = !isTrue  // false

// Increment and decrement (not available in Swift)
// Use += 1 and -= 1 instead
var counter = 5
counter += 1  // counter is now 6
counter -= 1  // counter is now 5

print("Negative: \(negativeNumber)")
print("Is false: \(isFalse)")
print("Counter: \(counter)")

🔹 Ternary Conditional Operator

The ternary operator is a shortcut for simple if-else statements:

// Ternary operator: condition ? valueIfTrue : valueIfFalse
let age = 18
let status = age >= 18 ? "Adult" : "Minor"

let score = 85
let grade = score >= 90 ? "A" : score >= 80 ? "B" : "C"

// Equivalent if-else statement
let temperature = 75
var weather: String
if temperature > 80 {
    weather = "Hot"
} else {
    weather = "Cool"
}

// Same result with ternary operator
let weatherTernary = temperature > 80 ? "Hot" : "Cool"

print("Status: \(status)")
print("Grade: \(grade)")
print("Weather: \(weatherTernary)")

🔹 Nil-Coalescing Operator

The nil-coalescing operator (??) provides a default value for optionals:

// Nil-coalescing operator: optional ?? defaultValue
let optionalName: String? = nil
let userName = optionalName ?? "Guest"

let optionalAge: Int? = 25
let userAge = optionalAge ?? 0

// Chaining nil-coalescing operators
let firstName: String? = nil
let lastName: String? = nil
let displayName = firstName ?? lastName ?? "Unknown User"

// Using with dictionary values
let userInfo = ["email": "[email protected]"]
let email = userInfo["email"] ?? "No email provided"
let phone = userInfo["phone"] ?? "No phone provided"

print("User: \(userName)")
print("Age: \(userAge)")
print("Display name: \(displayName)")
print("Email: \(email)")

🔹 Range Operators

Swift provides operators to create ranges of values:

// Closed range operator (includes both ends)
let closedRange = 1...5  // 1, 2, 3, 4, 5

// Half-open range operator (excludes upper bound)
let halfOpenRange = 1..<5  // 1, 2, 3, 4

// One-sided ranges
let fromStart = ...3     // up to and including 3
let toEnd = 2...         // from 2 to the end

// Using ranges in loops
print("Closed range:")
for number in 1...3 {
    print("Number: \(number)")
}

print("\nHalf-open range:")
for index in 0..<3 {
    print("Index: \(index)")
}

// Using ranges with arrays
let fruits = ["Apple", "Banana", "Cherry", "Date"]
let firstTwo = fruits[0..<2]  // ["Apple", "Banana"]
print("\nFirst two fruits: \(Array(firstTwo))")