Lesson 1: Programming in Xcode using Swift

// Explicit declaration results in a Double

let pi:Double = 3.14159

// Assigning a floating point literal results in a Double

let anotherPi = 3.14159

// Assigning a Double results in a Double

let xFactor = Double(3)

// Implicit declaration results in a Double

let anotherPi = 3.14159

// Expression with all integer literals results in an Int

let mySum = 2 + 3 + 4

// Expression with integers and floating point literals results in a Double

let secondSum = 2 + 1 + 0.14

Operators

// Assignment ( = )

var a = 5 // a is 5

var b = 2 // b is 2

// Arithmetic ( +, -, *, /, %, ++, — )

a= a + 3 // a is now 8

a= a – 2 // a is now 6

a= a * 4 // a is now 24

a= a / 2 // a is now 12

a= a % 5 // a is now 2

a = a++ // a is still 2

a = b++ // a is now 2, b is now 3
a = ++b // a is now 4, b is now 4
b = --b // b is now 3

// Compound Assignment ( +=, -=, *=, /= )

varx=5 //x  is5

vary=2 //y  is2

x += y //x is now 7
x -= 1 //x is now 6

x *= 4 //x is now 24

x /= 3 //x is now 8

 

// Unary Minus ( – )

x = -5 //x is now -5

y= x + 7 //y is now 2