Swift Notes

gistfile1.swift

/* Swift notes */

import Cocoa

/*  Use let to make a contant and var to make a variable, implicitly infer the type */

var cheesyVariable = 100
let cheesyConstant = 666
let implicitDouble = 70.0

//cheesyConstant++; //cheesyConstant is a constant, cannot modify it

/* 

Whenever possible, use let. It's a good practice and will allow the compiler to perform optimizations.

Specify the type after colon : 

*/

var explicitDouble: Double = 70;
let teamSize: Int = 100
let aintThisMad: Bool = true
var explicitString: String = "Lorem ipsum"
var inferredString = "סוף הדרך"
var 猫 = "cat"
let euroSymbol: Character = "€"

var emptyString = ""
var emptyString2 = String()

/* Use \() to include values in strings */

let steaks = 123;
let steakType = "sirloin"
let dinnerSummary = "I have \(steakType) \(steaks) steaks!"
let dinnerSummary2 = "Now I have \(steakType) \(steaks*10) steaks!"

let concatenateString = (dinnerSummary + " I changed my mind " + dinnerSummary2 + "and a " + 猫).uppercaseString

/*Use countElements to get length of the string */

concatenateString.substringFromIndex(countElements(concatenateString)-11)

/*use .componentsSeparatedByCharactersInSet() to explode string to array */

var myString = "One-Two-Three-1 2 3"
var array : String[] = myString.componentsSeparatedByCharactersInSet(NSCharacterSet (charactersInString: "- "))

/* optionals */
var optionalString: String? = "Hello"
optionalString == nil

var optionalName: String? = nil //"John Appleseed"
var greeting = "Hello!"
if let name = optionalName {
    greeting = "Hello, \(name)"
}

/* FOR IN */

let individualScores = [75, 43, 103, 87, 12]
var teamScore = 0
for score in individualScores {
    if score > 50 {
        teamScore += 3
    } else {
        teamScore += 1
    }
}
teamScore

var shoppingList: String[] = ["Eggs", "Milk"]
var arrayWithVariousTypes = [1, 1, 1, 1, 2, "asdf", shoppingList]
var airports: Dictionary<String, String> = ["TYO": "Tokyo", "DUB": "Dublin"]

arrayWithVariousTypes.count
arrayWithVariousTypes

if let airportName = airports["LAX"]{
    println("The name of the airport is \(airportName)")
    
} else {
    print("not found\n")
}

var dict = [
    "a" : 1,
    "b" : 2,
    "c" : 3
]

"Iterate"

for (key, val) in dict {
    println(key, " is ", val)
}