02 The Swift Language.md

SWIFT TOUR

• implicit variables and immutable variables

• explicit variables

• values need to be explicitly converted

• use () to convert a variable to a string (in quotes)

• arrays and dictionaries

To Do

• implicit and explicit variable data types
• strings
• string interpolation ()
• chars (converting string to array of chars).
• arrays
• introspection (type)
• enumerated
• characters
• repeat while
• conditional (if)
• optionals
• exit (quit script with exit code)

Membership

• enumerations (errors)
• exception handling & throwing errors
• guard let else
• switch
• type of

Contact

• declaring functions
• return types
• unused vars _
• functions that throw errors

---

Arrays

let colours:[String] = ["red", "orange", "green"]
print(colours.count)
print("\(colours)")

var shoppingList = [String]()
//shoppingList.append("bread")
shoppingList += ["Bread"]
shoppingList.append("butter")
print("\(shoppingList)")
for item in shoppingList {
  print("\(item)")
}

Dictionaries

var book   = [
  "isbn": "1491943122",
  "title": "Learning Node"
]

var ages = [String:Int]()
ages["john"] = 42
ages["jane"] = 24
print("\(ages)")
for (name, age) in ages {
  print("\(name) is \(age) years old")
}

struct

// normally functions use their parameter names as labels so you need to have a custom argument label before each parameter name.

func printPerson(withName name:String, andAge age:Int) {
  print("\(name) is \(age) years old")
}

printPerson(withName: "frank", andAge: 64)

// use _ if you want to omit the first argument label.
func add(_ num1:Int, and num2:Int) -> Int {
  return num1 + num2
}

print(add(24, and: 42))

OOP

• objects and classes
• importing from separate file
• create instance by putting parenthesis before class name.
• private instance variables
• properties (getters and setters)
• methods
• static

Async

• closures (callbacks)

Foundation Framework

Unit Testing

• importing XCUnit