Swift Tutorial - 1Jintin

Feature• Modern

• Static Language

• Type Safety & Inference

• Objective-C Compatible

• Open Source

Hello World

print(“Hello, world”)

Const vs Variable

var a = 1 a = 2

let b = 1 b = 2 // error

Type Safe

var a: Int = 1 var b: Double = 1.1 var c: [Int] = [1, 2, 3] var d: String = “hello” var e: Int = 1.1 // error

Type Inference

var a: Int = 1

var b = 1 // b is Int too

Optional

var a: Int = nil // error

var b: Int? = nil

Optional

var a: Int = 1 print(a) // 1

var b: Int? = 1 print(b) // Optional(1)

Unwrapped Optional

var b: Int? = 1

print(b) // Optional(1) print(b!) // 1

Control Flow: if

if a == 1 { print(“a = 1”) } else { // do something }

Control Flow: if let

var a: Int? = 1

if let b = a { print(b) }

Exercise

// print “Hello, [name]” if name not nil, else print “Hello there.”

var name: String?