Do a simple test

if condition {
// do something
} else {
// do something else
}

Basic function without parameters

func doSomething() {
// some code
}

Function with arguments

func doSomething (x: Int, y: Int){
  // do it
}

Function with String input and String output

func sayHi (name: String) -> String {
  return "Hi \(name)"
}

Basic integer iteration

for index in 0...10 {
  // do it from 0 to 10 included
}

Iterate over elements of an array

var myArray = ["toto", "titi"]
for firstName in myArray {
  //do something with firstName
}

Iterate over elements of a dictionary

var myDict = ["John" : 14, "Paul" : 18]
for (name, age) in myDict {
  print("\(name) is \(age)")
}

Iterate over an array with index

for (index, value) in myArray.enumerated() {
}

Simple switch

var myNumber = 2
switch myNumber {
 case 1:
 // do for 1
 case 2:
 // do for 2
 default:
}

A break statement is not required

Simple while loop

while condition {
// do something 
}

The code inside may never be executed. Beware of endless loops!

Simple repeat loop

repeat {
// do something
} while condition

Something is done at least once

Switch with interval matching.

This is specific to Swift.

switch myNumber {
case 0..<8:
  //
  case 8..<10:
  //
  default:
}

break

break terminates the execution of the control flow.

Can be used in a switch, or any loop statement : for, repeat, while

Function with multiple output

func sinCos (x : Double) -> (sin: Double, cos: Double) {
return (sin(x), cos(x))
}
// the output is a tuple and is accessed like this:
let cosx = sinCos(M_PI).cos
// returns -1